23 resultados para asymmetries

em Queensland University of Technology - ePrints Archive


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Many cognitive neuroscience studies show that the ability to attend to and identify global or local information is lateralised between the two hemispheres in the human brain; the left hemisphere is biased towards the local level, whereas the right hemisphere is biased towards the global level. Results of two studies show attention-focused people with a right ear preference (biased towards the left hemisphere) are better at local tasks, whereas people with a left ear preference (biased towards the right hemisphere) are better at more global tasks. In a third study we determined if right hemisphere-biased followers who attend to global stimuli are likely to have a stronger relationship between attention and globally based supervisor ratings of performance. Results provide evidence in support of this hypothesis. Our research supports our model and suggests that the interaction between attention and lateral preference is an important and novel predictor of work-related outcomes.

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Using the Education Queensland Reform Agenda to illustrate examples and approaches to education reform, this article discusses education reform for at-risk youth. It argues that the characteristics of modernity, the rise of Mode 2 Society, and the power asymmetries associated with the emergence of the politico-economic will contain the reform ambitions of the Education Queensland and other education reform agendas. It is proposed that the State adopt a transgressive and complimentary set of reform strategies including the adoption of distributed governance, making available meaningful school performance data, encouraging experimentation and facilitating broad stakeholder, community and neighbourhood engagement in school planning and operations. The article argues that measures such as these will assist to mobilize trust, minimise social fragmentation, generate and regenerate community resources, build cohesion, foster the socio-cultural-self-identities of 'at-risk' youth and will assist youth to achieve full participation in a robust and vibrant democracy.

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Market failures involving the sale of complex merchandise, such as residential property, financial products and credit, have principally been attributed to information asymmetries. Existing legislative and regulatory responses were developed having regard to consumer protection policies based on traditional economic theories that focus on the notion of the ‘rational consumer’. Governmental responses therefore seek to impose disclosure obligations on sellers of complex goods or products to ensure that consumers have sufficient information upon which to make a decision. Emergent research, based on behavioural economics, challenges traditional ideas and instead focuses on the actual behaviour of consumers. This approach suggests that consumers as a whole do not necessarily benefit from mandatory disclosure because some, if not most, consumers do not pay attention to the disclosed information before they make a decision to purchase. The need for consumer policies to take consumer characteristics and behaviour into account is being increasingly recognised by governments, and most recently in the policy framework suggested by the Australian Productivity Commission

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Animal models of refractive error development have demonstrated that visual experience influences ocular growth. In a variety of species, axial anisometropia (i.e. a difference in the length of the two eyes) can be induced through unilateral occlusion, image degradation or optical manipulation. In humans, anisometropia may occur in isolation or in association with amblyopia, strabismus or unilateral pathology. Non-amblyopic myopic anisometropia represents an interesting anomaly of ocular growth, since the two eyes within one visual system have grown to different endpoints. These experiments have investigated a range of biometric, optical and mechanical properties of anisometropic eyes (with and without amblyopia) with the aim of improving our current understanding of asymmetric refractive error development. In the first experiment, the interocular symmetry in 34 non-amblyopic myopic anisometropes (31 Asian, 3 Caucasian) was examined during relaxed accommodation. A high degree of symmetry was observed between the fellow eyes for a range of optical, biometric and biomechanical measurements. When the magnitude of anisometropia exceeded 1.75 D, the more myopic eye was almost always the sighting dominant eye. Further analysis of the optical and biometric properties of the dominant and non-dominant eyes was conducted to determine any related factors but no significant interocular differences were observed with respect to best-corrected visual acuity, corneal or total ocular aberrations during relaxed accommodation. Given the high degree of symmetry observed between the fellow eyes during distance viewing in the first experiment and the strong association previously reported between near work and myopia development, the aim of the second experiment was to investigate the symmetry between the fellow eyes of the same 34 myopic anisometropes following a period of near work. Symmetrical changes in corneal and total ocular aberrations were observed following a short reading task (10 minutes, 2.5 D accommodation demand) which was attributed to the high degree of interocular symmetry for measures of anterior eye morphology, and corneal biomechanics. These changes were related to eyelid shape and position during downward gaze, but gave no clear indication of factors associated with near work that might cause asymmetric eye growth within an individual. Since the influence of near work on eye growth is likely to be most obvious during, rather than following near tasks, in the third experiment the interocular symmetry of the optical and biometric changes was examined during accommodation for 11 myopic anisometropes. The changes in anterior eye biometrics associated with accommodation were again similar between the eyes, resulting in symmetrical changes in the optical characteristics. However, the more myopic eyes exhibited slightly greater amounts of axial elongation during accommodation which may be related to the force exerted by the ciliary muscle. This small asymmetry in axial elongation we observed between the eyes may be due to interocular differences in posterior eye structure, given that the accommodative response was equal between eyes. Using ocular coherence tomography a reduced average choroidal thickness was observed in the more myopic eyes compared to the less myopic eyes of these subjects. The interocular difference in choroidal thickness was correlated with the magnitude of spherical equivalent and axial anisometropia. The symmetry in optics and biometrics between fellow eyes which have undergone significantly different visual development (i.e. anisometropic subjects with amblyopia) is also of interest with respect to refractive error development. In the final experiment the influence of altered visual experience upon corneal and ocular higher-order aberrations was investigated in 21 amblyopic subjects (8 refractive, 11 strabismic and 2 form deprivation). Significant differences in aberrations were observed between the fellow eyes, which varied according to the type of amblyopia. Refractive amblyopes displayed significantly higher levels of 4th order corneal aberrations (spherical aberration and secondary astigmatism) in the amblyopic eye compared to the fellow non-amblyopic eye. Strabismic amblyopes exhibited significantly higher levels of trefoil, a third order aberration, in the amblyopic eye for both corneal and total ocular aberrations. The results of this experiment suggest that asymmetric visual experience during development is associated with asymmetries in higher-order aberrations, proportional to the magnitude of anisometropia and dependent upon the amblyogenic factor. This suggests a direct link between the development of higher-order optical characteristics of the human eye and visual feedback. The results from these experiments have shown that a high degree of symmetry exists between the fellow eyes of non-amblyopic myopic anisometropes for a range of biomechanical, biometric and optical parameters for different levels of accommodation and following near work. While a single specific optical or biomechanical factor that is consistently associated with asymmetric refractive error development has not been identified, the findings from these studies suggest that further research into the association between ocular dominance, choroidal thickness and higher-order aberrations with anisometropia may improve our understanding of refractive error development.

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This study compared the corneal and total higher order aberrations between the fellow eyes in monocular amblyopia. Nineteen amblyopic subjects (8 refractive and 11 strabismic) (mean age 30 ± 11 years) were recruited. A range of biometric and optical measurements were collected from the amblyopic and non-amblyopic eye including; axial length, corneal topography and total higher order aberrations. For a sub-group of eleven non-presbyopic subjects (6 refractive and 5 strabismic amblyopes, mean age 29 ± 10 years) total higher order aberrations were also measured during accommodation (2.5 D stimuli). Amblyopic eyes were significantly shorter and more hyperopic compared to non-amblyopic eyes and the interocular difference in axial length correlated with both the magnitude of anisometropia and amblyopia (both p < 0.01). Significant differences in higher order aberrations were observed between fellow eyes, which varied with the type of amblyopia. Refractive amblyopes displayed higher levels of 4th order corneal aberrations C(4, 0)(spherical aberration), C(4, 2)(secondary astigmatism 90°) and C(4, −2)(secondary astigmatism along 45°) in the amblyopic eye compared to the non-amblyopic eye. Strabismic amblyopes exhibited significantly higher levels of C(3, 3)(trefoil) in the amblyopic eye for both corneal and total higher order aberrations. During accommodation, the amblyopic eye displayed a significantly greater lag of accommodation compared to the non-amblyopic eye, while the changes in higher order aberrations were similar in magnitude between fellow eyes. Asymmetric visual experience during development appears to be associated with asymmetries in higher order aberrations, in some cases proportional to the magnitude of anisometropia and dependent upon the amblyogenic factor.

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The aetiology behind overuse injuries such as stress fractures is complex and multi-factorial. In sporting events where the loading is likely to be uneven (e.g. hurdling and jumps), research has suggested that the frequency of stress fractures seems to favour the athlete’s dominant limb. The tendency for an individual to have a preferred limb for voluntary motor acts makes limb selection a possible factor behind the development of unilateral overuse injuries, particularly when repeatedly used during high loading activities. The event of sprint hurdling is well suited for the study of loading asymmetry as the hurdling technique is repetitive and the limb movement asymmetrical. Of relevance to this study is the high incidence of Navicular Stress Fractures (NSF) in hurdlers, with suggestions there is a tendency for the fracture to develop in the trail leg foot, although this is not fully accepted. The Ground Reaction Force (GRF) with each foot contact is influenced by the hurdle action, with research finding step-to-step loading variations. However, it is unknown if this loading asymmetry extends to individual forefoot joints, thereby influencing stress fracture development. The first part of the study involved a series of investigations using a commercially available matrix style in-shoe sensor system (FscanTM, Tekscan Inc.). The suitability of insole sensor systems and custom made discrete sensors for use in hurdling-related training activities was assessed. The methodology used to analyse foot loading with each technology was investigated. The insole and discrete sensors systems tested proved to be unsuitable for use during full pace hurdling. Instead, a running barrier task designed to replicate the four repetitive foot contacts present during hurdling was assessed. This involved the clearance of a series of 6 barriers (low training hurdles), place in a straight line, using 4 strides between each. The second part of the study involved the analysis of "inter-limb" and "within foot loading asymmetries" using stance duration as well as vertical GRF under the Hallux (T1), the first metatarsal head (M1) and the central forefoot peak pressure site (M2), during walking, running, and running with barrier clearances. The contribution to loading asymmetry that each of the four repetitive foot contacts made during a series of barrier clearances was also assessed. Inter-limb asymmetry, in forefoot loading, occurred at discrete forefoot sites in a non-uniform manner across the three gait conditions. When the individual barrier foot contacts were compared, the stance duration was asymmetrical and the proportion of total forefoot load at M2 was asymmetrical. There were no significant differences between the proportion of forefoot load at M1, compared to M2; for any of the steps involved in the barrier clearance. A case study testing experimental (discrete) sensors during full pace sprinting and hurdling found that during both gait conditions, the trail limb experienced the greater vertical GRF at M1 and M2. During full pace hurdling, increased stance duration and vertical loading was a characteristic of the trail limb hurdle foot contacts. Commercially available in-shoe systems are not suitable for on field assessment of full pace hurdling. For the use of discrete sensor technology to become commonplace in the field, more robust sensors need to be developed.

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Triggered by highly publicized corporate scandals, changing societal expectations and the collapse of financial markets, the roles of boards of directors have changed significantly in safeguarding the interest of shareholders and other stakeholders. Yet relatively little is known about contemporary challenges non-executive directors face and whether their boards are well-equipped for their new tasks. Based on self-assessment reports by supervisory boards, a survey and interviews with supervisory board members, this paper investigates the challenges non-executive directors face in the Netherlands, particularly after a decade of corporate governance reform. Non-executive directors’ inadequate role in scrutinizing executive directors’ performance, information asymmetries and dysfunctional working relationships between executive and non-executive directors are among the greatest challenges indicated by non-executive directors on Dutch supervisory boards. The paper discusses several implications for scholars and practitioners and provides a unique insight in boardroom dynamics (word count: 138).

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Purpose: This study explores how non-executive directors address governance problems on Dutch two-tier boards. Within this board model, challenges might be particularly difficult to address due to the formal separation of management boards’ decision-management from supervisory boards’ decision-control roles. Design/methodology/approach: Semi-structured interviews and a questionnaire among non-executive directors provide unique insights into three major challenges in the boardrooms of two-tier boards in the Netherlands. Findings: The study indicates that non-executive directors mainly experience challenges in three areas: the ability to ask management critical questions, information asymmetries between the management and supervisory boards and the management of the relationship between individual executive and non-executive directors. The qualitative in-depth analysis reveals the complexity of the contributing factors to problems in the boardroom and the range of process and social interventions non-executive directors use to address boardroom issues with management and the organization of the board. Practical implications: While policy makers have been largely occupied with the ‘right’ board composition, the results highlight the importance of adequately addressing operational challenges in the boardroom. The results emphasize the importance of a better understanding of board processes and the need of non-executive directors to carefully manage relationships in and around the boardroom. Originality/value: Whereas most studies have focussed on regulatory initiatives to improve the functioning of boards (e.g., the independence of the board), this study explores how non-executive directors attempt to enhance the effectiveness of boards on which they serve.

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Purpose: To examine between eye differences in corneal higher order aberrations and topographical characteristics in a range of refractive error groups. Methods: One hundred and seventy subjects were recruited including; 50 emmetropic isometropes, 48 myopic isometropes (spherical equivalent anisometropia ≤ 0.75 D), 50 myopic anisometropes (spherical equivalent anisometropia ≥ 1.00 D) and 22 keratoconics. The corneal topography of each eye was captured using the E300 videokeratoscope (Medmont, Victoria, Australia) and analyzed using custom written software. All left eye data were rotated about the vertical midline to account for enantiomorphism. Corneal height data were used to calculate the corneal wavefront error using a ray tracing procedure and fit with Zernike polynomials (up to and including the eighth radial order). The wavefront was centred on the line of sight by using the pupil offset value from the pupil detection function in the videokeratoscope. Refractive power maps were analysed to assess corneal sphero-cylindrical power vectors. Differences between the more myopic (or more advanced eye for keratoconics) and the less myopic (advanced) eye were examined. Results: Over a 6 mm diameter, the cornea of the more myopic eye was significantly steeper (refractive power vector M) compared to the fellow eye in both anisometropes (0.10 ± 0.27 D steeper, p = 0.01) and keratoconics (2.54 ± 2.32 D steeper, p < 0.001) while no significant interocular difference was observed for isometropic emmetropes (-0.03 ± 0.32 D) or isometropic myopes (0.02 ± 0.30 D) (both p > 0.05). In keratoconic eyes, the between eye difference in corneal refractive power was greatest inferiorly (associated with cone location). Similarly, in myopic anisometropes, the more myopic eye displayed a central region of significant inferior corneal steepening (0.15 ± 0.42 D steeper) relative to the fellow eye (p = 0.01). Significant interocular differences in higher order aberrations were only observed in the keratoconic group for; vertical trefoil C(3,-3), horizontal coma C(3,1) secondary astigmatism along 45 C(4, -2) (p < 0.05) and vertical coma C(3,-1) (p < 0.001). The interocular difference in vertical pupil decentration (relative to the corneal vertex normal) increased with between eye asymmetry in refraction (isometropia 0.00 ± 0.09, anisometropia 0.03 ± 0.15 and keratoconus 0.08 ± 0.16 mm) as did the interocular difference in corneal vertical coma C (3,-1) (isometropia -0.006 ± 0.142, anisometropia -0.037 ± 0.195 and keratoconus -1.243 ± 0.936 μm) but only reached statistical significance for pair-wise comparisons between the isometropic and keratoconic groups. Conclusions: There is a high degree of corneal symmetry between the fellow eyes of myopic and emmetropic isometropes. Interocular differences in corneal topography and higher order aberrations are more apparent in myopic anisometropes and keratoconics due to regional (primarily inferior) differences in topography and between eye differences in vertical pupil decentration relative to the corneal vertex normal. Interocular asymmetries in corneal optics appear to be associated with anisometropic refractive development.

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This paper focuses on Australian development firms in the console and mobile games industry in order to understand how small firms in a geographically remote and marginal position in the global industry are able to relate to global firms and capture revenue share. This paper shows that, while technological change in the games industry has resulted in the emergence of new industry segments based on transactional rather than relational forms of economic coordination, in which we might therefore expect less asymmetrical power relations, lead firms retain a position of power in the global games entertainment industry relative to remote developers. This has been possible because lead firms in the emerging mobile devices market have developed and sustained bottlenecks in their segment of the industry through platform competition and the development of an intensely competitive ecosystem of developers. Our research shows the critical role of platform competition and bottlenecks in influencing power asymmetries within global markets.

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This thesis extends current understanding in management consulting research by investigating the ways in which management consultants and their clients shaped knowing over the course of nine different consulting engagements. The research illuminates the client experience of using consulting knowledge in organisations, and proposes a theoretical reconceptualisation of knowledge shaping in consulting engagements which incorporates how the knowing client is enacted. The research shows that knowledge shaping activities are planned and enacted to support novelty reduction in consulting engagements; that asymmetries in the structuring of the consultant–client relationship hamper knowledge transformation and the establishment of knowing; and that understanding of how the role identities of consultants and clients are established and maintained over the course of an engagement is integral to understanding knowledge shaping in consulting engagements.

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Contralateral bones are often used in many medical applications but it is assumed that their bilateral differences are insignificant. Previous studies used a limited number of distance measurements in quantifying the corresponding differences; therefore, little is known about their bilateral 3D surface asymmetries. The aim of the study is to develop a comprehensive method to quantify geometrical asymmetries between the left and right tibia in order to provide first results on whether the contralateral tibia can be used as an equivalent reference. In this study, 3D bone models were reconstructed from CT scans of seven tibiae pairs, and 34 variables consisting of 2D and 3D measurements were measured from various anatomical regions. All 2D measurements, and lateral plateau and distal subchondral bone surface measurements showed insignificant differences (p > 0.05), but the rest of the surfaces showed significant differences (p < 0.05). Our results suggest that the contralateral tibia can be used as a reference especially in surgical applications such as articular reconstructions since the bilateral differences in the subchondral bone surfaces were less than 0.3 mm. The method can also be potentially transferable to other relevant studies that require the accurate quantification of bone bilateral asymmetries.

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This thesis examines the question why the automotive mode and the large technological system it creates, continues to dominate urban transport systems despite the availability of more cost-efficient alternatives. A number of theoretical insights are developed into the way these losses evolve from path dependent growth, and lead to market failure and lock-in. The important role of asymmetries of influence is highlighted. A survey of commuters in Jakarta Indonesia is used to provide a measure of transport modal lock-in (TML) in a developing country conurbation. A discrete choice experiment is used to provide evidence for the thesis central hypothesis that in such conurbations there is a high level of commuter awareness of the negative externalities generated by TML which can produce a strong level of support for its reversal. Why TML nevertheless remains a strong and durable feature of the transport system is examined with reference to the role of asymmetries of influence.

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New public management (NPFM), with its hands-on, private sector-style performance measurement, output control, parsimonious use of resources, disaggreation of public sector units and greater competition in the public sector, has significantly affected charitable and nonprofit organisations delivering community services (Hood, 1991; Dunleavy, 1994; George & Wilding, 2002). The literature indicates that nonprofit organisations under NPM believe they are doing more for less: while administration is increasing, core costs are not being met; their dependence on government funding comes at the expense of other funding strategies; and there are concerns about proportionality and power asymmetries in the relationship (Kerr & Savelsberg, 2001; Powell & Dalton, 2011; Smith, 2002, p. 175; Morris, 1999, 2000a). Government agencies are under increased pressure to do more with less, demonstrate value for money, measure social outcomes, not merely outputs and minimise political risk (Grant, 2008; McGreogor-Lowndes, 2008). Government-community service organisation relationships are often viewed as 'uneasy alliances' characterised by the pressures that come with the parties' differing roles and expectations and the pressures that come with the parties' differing roles and expectations and the pressurs of funding and security (Productivity Commission, 2010, p. 308; McGregor-Lowndes, 2008, p. 45; Morris, 200a). Significant community services are now delivered to citizens through such relationships, often to the most disadvantaged in the community, and it is important for this to be achieved with equity, efficiently and effectively. On one level, the welfare state was seen as a 'risk management system' for the poor, with the state mitigating the risks of sickness, job loss and old age (Giddens, 1999) with the subsequent neoliberalist outlook shifting this risk back to households (Hacker, 2006). At the core of this risk shift are written contracts. Vincent-Jones (1999,2006) has mapped how NPM is characterised by the use of written contracts for all manner of relations; e.g., relgulation of dealings between government agencies, between individual citizens and the state, and the creation of quais-markets of service providers and infrastructure partners. We take this lens of contracts to examine where risk falls in relation to the outsourcing of community services. First we examine the concept of risk. We consider how risk might be managed and apportioned between governments and community serivce organisations (CSOs) in grant agreements, which are quasiy-market transactions at best. This is informed by insights from the law and economics literature. Then, standard grant agreements covering several years in two jurisdictions - Australia and the United Kingdom - are analysed, to establish the risk allocation between government and CSOs. This is placed in the context of the reform agenda in both jurisdictions. In Australia this context is th enonprofit reforms built around the creation of a national charities regulator, and red tape reduction. In the United Kingdom, the backdrop is the THird Way agenda with its compacts, succeed by Big Society in a climate of austerity. These 'case studies' inform a discussion about who is best placed to bear and manage the risks of community service provision on behalf of government. We conclude by identifying the lessons to be learned from our analysis and possible pathways for further scholarship.

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Diffusion imaging can map anatomical connectivity in the living brain, offering new insights into fundamental questions such as how the left and right brain hemispheres differ. Anatomical brain asymmetries are related to speech and language abilities, but less is known about left/right hemisphere differences in brain wiring. To assess this, we scanned 457 young adults (age 23.4±2.0 SD years) and 112 adolescents (age 12-16) with 4-Tesla 105-gradient high-angular resolution diffusion imaging. We extracted fiber tracts throughout the brain with a Hough transform method. A 70×70 connectivity matrix was created, for each subject, based on the proportion of fibers intersecting 70 cortical regions. We identified significant differences in the proportions of fibers intersecting left and right hemisphere cortical regions. The degree of asymmetry in the connectivity matrices varied with age, as did the asymmetry in network topology measures such as the small-world effect.