Queensland University of Technology

About: Queensland University of Technology is a education organization based out in Brisbane, Queensland, Australia. It is known for research contribution in the topics: Population & Context (language use). The organization has 14188 authors who have published 55022 publications receiving 1496237 citations. The organization is also known as: QUT.

Biofabrication of osteochondral tissue equivalents by printing topologically defined, cell-laden hydrogel scaffolds

Abstract: Osteochondral defects are prone to induce osteoarthritic degenerative changes. Many tissue-engineering approaches that aim to generate osteochondral implants suffer from poor tissue formation and compromised integration. This illustrates the need for further improvement of heterogeneous tissue constructs. Engineering of these structures is expected to profit from strategies addressing the complexity of tissue organization and the simultaneous use of multiple cell types. Moreover, this enables the investigation of the effects of three-dimensional (3D) organization and architecture on tissue function. In the present study, we characterize the use of a 3D fiber deposition (3DF) technique for the fabrication of cell-laden, heterogeneous hydrogel constructs for potential use as osteochondral grafts. Changing fiber spacing or angle of fiber deposition yielded scaffolds of varying porosity and elastic modulus. We encapsulated and printed fluorescently labeled human chondrocytes and osteogenic progenitors in alginate hydrogel yielding scaffolds of 1×2 cm with different parts for both cell types. Cell viability remained high throughout the printing process, and cells remained in their compartment of the printed scaffold for the whole culture period. Moreover, distinctive tissue formation was observed, both in vitro after 3 weeks and in vivo (6 weeks subcutaneously in immunodeficient mice), at different locations within one construct. These results demonstrate the possibility of manufacturing viable centimeter-scaled structured tissues by the 3DF technique, which could potentially be used for the repair of osteochondral defects.

The Corporate Governance Effects of Audit Committees

Abstract: Arguments associated with the promotion of audit committees in many countries are premised on their potential for alleviating weaknesses in corporate governance This paper provides a synthesis and evaluation of empirical research on the governance effects associated with audit committees Given recent policy recommendations in several countries aimed at strengthening these committees, it is important to establish what research evidence demonstrates about their existing governance contribution A framework for analyzing the impact of audit committees is described, identifying potential perceived effects which may have led to their adoption and documented effects on aspects of the audit function, on financial reporting quality and on corporate performance It is argued that there is only limited and mixed evidence of effects to support claims and perceptions about the value of audit committees for these elements of governance It is also shown that most of the existing research has focused on factors associated with audit committee existence, characteristics and measures of activity and there is very little evidence on the processes associated with the operation of audit committees and the manner in which they influence organizational behaviour It is clear that there is no automatic relationship between the adoption of audit committee structures or characteristics and the achievement of particular governance effects, and caution may be needed over expectations that greater codification around factors such as audit committee members' independence and expertise as the means of "correcting" past weaknesses in the arrangements for audit committees The most fundamental question concerning what difference audit committees make in practice continues to be an important area for research development For future research we suggest (i) greater consideration of the organizational and institutional contexts in which audit committees operate; (ii) explicit theorization of the processes associated with audit committee operation; (iii) complementing extant research methods with field studies; and (iv) investigation of unintended (behavioural) as well as expected consequences of audit committees

Confinement and propagation characteristics of subwavelength plasmonic modes

Abstract: We have studied subwavelength confinement of the surface plasmon polariton modes of various plasmonic waveguides and examined their relative merits using a graphical parametric representation of their confinement and propagation characteristics. While the same plasmonic phenomenon governs mode confinement in all these waveguides, the various architectures can exhibit distinctive behavior in terms of effective mode area and propagation distance. We found that the waveguides based on metal and one dielectric material show a similar trade-off between energy confinement and propagation distance. However, a hybrid plasmon waveguide, incorporating metal, low index and high index dielectric materials, exhibits longer propagation distances for the same degree of confinement. We also point out that plasmonic waveguides with sharp features can provide an extremely strong local field enhancement, which is not necessarily accompanied by strong confinement of the total electromagnetic energy. In these waveguides, a mode may couple strongly to nearby atoms, but suffer relatively low propagation losses due to weak confinement.

Being stoned: a review of self-reported cannabis effects.

Abstract: Although there has been considerable research into the adverse effects of cannabis, less attention has been directed toward subjective effects that may be associated with ongoing cannabis use. Examination of self-reported cannabis effects is an important issue in understanding the widespread use of cannabis. While reviews have identified euphoria as a primary factor in maintaining cannabis use, relaxation is the effect reported most commonly in naturalistic studies of cannabis users, irrespective of the method used. Self-reported effects in 12 naturalistic and 18 laboratory studies were compared. Regardless of methodology there was considerable variation in the effects experienced. Variation has been reported in terms of opposite effects being experienced by different individuals, variation of effects by individuals within a single occasion and between occasions of use. Factors that might explain this variation are outlined. Limitations of the available literature and suggested directions for future research are discussed.