7,123 research outputs found
Equine mesenchymal stromal cells and embryo-derived stem cells are immune privileged in vitro
Tomorrow’s accounting and society’s future
Despite the growing trend towards greater corporate accountability and increasing revival of social accounting there remains a significant gap between what organisations do, what they are willing to report, and the rights of society. In this concluding chapter, we consider the realities and myths of social accounting in relation to tomorrow’s accounting and society’s future. The chapter begins with a discussion of accounting as a social and institutional practice. It then moves on to consider the issues raised throughout the book and reflects on how the public sector, third sector, cooperatives and family businesses need to adapt and respond to demands for increased social responsibility and demonstrate this through a social accounting and accountability system. The chapter concludes with a discussion of the changing nature of accountability and social accounting, future directions and potential developments within the social accounting arena
Singular Laplacian Growth
The general equations of motion for two dimensional Laplacian growth are
derived using the conformal mapping method. In the singular case, all
singularities of the conformal map are on the unit circle, and the map is a
degenerate Schwarz-Christoffel map. The equations of motion describe the
motions of these singularities. Despite the typical fractal-like outcomes of
Laplacian growth processes, the equations of motion are shown to be not
particularly sensitive to initial conditions. It is argued that the sensitivity
of this system derives from a novel cause, the non-uniqueness of solutions to
the differential system. By a mechanism of singularity creation, every solution
can become more complex, even in the absence of noise, without violating the
growth law. These processes are permitted, but are not required, meaning the
equation of motion does not determine the motion, even in the small.Comment: 8 pages, Latex, 4 figures, Submitted to Phys. Rev.
Ultraviolet relaxation dynamics of aniline, N, N-dimethylaniline and 3,5-dimethylaniline at 250 nm
Structure–property insights into nanostructured electrodes for Li-ion batteries from local structural and diffusional probes
Microwave heating presents a faster, lower energy synthetic methodology for the realization of functional materials. Here, we demonstrate for the first time that employing this method also leads to a decrease in the occurrence of defects in olivine structured LiFe1−xMnxPO4. For example, the presence of antisite defects in this structure precludes Li+ diffusion along the b-axis leading to a significant decrease in reversible capacities. Total scattering measurements, in combination with Li+ diffusion studies using muon spin relaxation (μ+SR) spectroscopy, reveal that this synthetic method generates fewer defects in the nanostructures compared to traditional solvothermal routes. Our interest in developing these routes to mixed-metal phosphate LiFe1−xMnxPO4 olivines is due to the higher Mn2+/3+ redox potential in comparison to the Fe2+/3+ pair. Here, single-phase LiFe1−xMnxPO4 (x = 0, 0.25, 0.5, 0.75 and 1) olivines have been prepared following a microwave-assisted approach which allows for up to 4 times faster reaction times compared to traditional solvothermal methods. Interestingly, the resulting particle morphology is dependent on the Mn content. We also examine their electrochemical performance as active electrodes in Li-ion batteries. These results present microwave routes as highly attractive for reproducible, gram-scale syntheses of high quality nanostructured electrodes which display close to theoretical capacity for the full iron phase
Efficient public-key cryptography with bounded leakage and tamper resilience
We revisit the question of constructing public-key encryption and signature schemes with security in the presence of bounded leakage and tampering memory attacks. For signatures we obtain the first construction in the standard model; for public-key encryption we obtain the first construction free of pairing (avoiding non-interactive zero-knowledge proofs). Our constructions are based on generic building blocks, and, as we show, also admit efficient instantiations under fairly standard number-theoretic assumptions.
The model of bounded tamper resistance was recently put forward by Damgård et al. (Asiacrypt 2013) as an attractive path to achieve security against arbitrary memory tampering attacks without making hardware assumptions (such as the existence of a protected self-destruct or key-update mechanism), the only restriction being on the number of allowed tampering attempts (which is a parameter of the scheme). This allows to circumvent known impossibility results for unrestricted tampering (Gennaro et al., TCC 2010), while still being able to capture realistic tampering attack
Amenable actions, free products and a fixed point property
We investigate the class of groups admitting an action on a set with an
invariant mean. It turns out that many free products admit such an action. We
give a complete characterisation of such free products in terms of a strong
fixed point property.Comment: 12 page
The Case for Quantum Key Distribution
Quantum key distribution (QKD) promises secure key agreement by using quantum
mechanical systems. We argue that QKD will be an important part of future
cryptographic infrastructures. It can provide long-term confidentiality for
encrypted information without reliance on computational assumptions. Although
QKD still requires authentication to prevent man-in-the-middle attacks, it can
make use of either information-theoretically secure symmetric key
authentication or computationally secure public key authentication: even when
using public key authentication, we argue that QKD still offers stronger
security than classical key agreement.Comment: 12 pages, 1 figure; to appear in proceedings of QuantumComm 2009
Workshop on Quantum and Classical Information Security; version 2 minor
content revision
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