Annular Defects Impair the Mechanical Stability of the Intervertebral Disc.

Study Design: A biomechanical study.

Objectives: The purpose of this study was to investigate the effects of cruciform and square incisions of annulus fibrosus (AF) on the mechanical stability of bovine intervertebral disc (IVD) in multiple degrees of freedom.

Methods: Eight bovine caudal IVD motion segments (bone-disc-bone) were obtained from the local abattoir.

A novel double-image encryption scheme based on cross-image pixel scrambling in gyrator domains.

Recently, a number of double-image cryptosystems have been developed. However, there are notable security performance differences between the two encryption channels in these algorithms. This weakness downgrades the security level and practicability of these cryptosystems, as the cryptosystems cannot guarantee all the input images be transmitted in the channel with higher security level.

An improved permutation-diffusion type image cipher with a chaotic orbit perturbing mechanism.

During the past decades, chaos-based permutation-diffusion type image cipher has been widely investigated to meet the increasing demand for real-time secure image transmission over public networks. However, the existing researches almost exclusively focus on the improvements of the permutation and diffusion methods independently, without consideration of cooperation between the two processes. In this paper, an improved permutation-diffusion type image cipher with a chaotic orbit perturbing mechanism is proposed.