Introduction.

This article introduces the current issue of Health Psychology. The call for early intervention to prevent adulthood health problems and the need to consider each period of children's lives within its developmental perspective are the main emphases in this special issue of the journal. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Fabrication of Arsenic Sulfide Optical Fiber with Low Hydrogen Impurities

Arsenic sulfide glass optical fibers typically possess extrinsic absorption bands in the infrared wavelength region associated with residual hydrogen and oxygen related impurities, despite using purified precursors. We report a purification process based on the addition of tellurium tetrachloride (TeCl₄) to the glass. During melting, the chlorine from TeCl₄ reacts with the hydrogen impurities to produce volatile products (e.g., HCl) that can be removed by subsequent dynamic distillation. The processing conditions have been modified accordingly to produce optical fibers with significantly reduced loss due to hydrogen sulfide impurity content (1.5 dB/m).     

Modeling transient slag-layer phenomena in the shell/mold gap in continuous casting of steel

Mold-slag friction and fracture may cause heat-transfer variations in continuous casting, which leads to steel shell temperature and stress variations, resulting in surface cracks. Analytical transient models of liquid slag flow and solid slag stress have been coupled with a finite-difference model of heat transfer in the mold, gap, and steel shell to predict transient shear stress, friction, slip, and fracture of the slag layers. The models are validated by comparing with numerical models and plant measurements of mold friction. Using reported slag-fracture strength and time-temperature-transformation (TTT) diagrams, the models are applied to study the effect of casting speed and mold-powder viscosity properties on slag-layer behavior between the oscillating mold wall and the solidifying steel shell. The study finds that liquid-slag lubrication would produce negligible stresses. A lower mold-slag consumption rate leads to high solid friction and results in solid-slag-layer fracture and movement below a critical value. Crystalline slag tends to fracture near the meniscus and glassy slag tends to fracture near the mold exit. A medium casting speed may be the safest to avoid slag fracture, due to its having the lowest critical lubrication consumption rate. The high measured friction force in operating casters could be due to three sources: an intermittent moving solid slag layer, excessive mold taper, or mold misalignment. Other symbols are defined in Table I     

高清晰光盘格式陷入“低水平”竞争

蓝色激光（Blu-ray，简称蓝光，以下同）光盘和HD DVD均开始进入量产，但格式大战的赢家还不明朗。红色激光：简称红光，以下同）格式仍是某些应用的可靠替代方案，但用户版权限制和显示器与视觉的限制使格式的未来令人疑惑。     

An analysis of the Slapper worm

We can prove that the Slapper is a variation of the Apache Scalper worm by comparing the source code. Modifications introduced in the Slapper worm improved the robustness and efficiency of its predecessor's simplistic P2P networking capabilities. Slapper's author also removed certain features from the original-either because they were redundant or to reduce the perception that it was a tool developed to cause direct harm to networks. Among the features the author removed from the Slapper were capabilities to update itself from a remotely specified Web server (perhaps to prevent someone else from replacing this version with a new one), to attack and infect a host specified with a controlling program, and to send spans. Interestingly, the ability to execute distributed denial-of-service attacks on a controlling user's behalf was kept intact. Slapper's author attempted to make communications with a remote controlling program as stealthy and untraceable as possible by removing several commands to query status and obtain feedback from Slapper nodes.     

Principal axes and surface fitting methods for three-dimensional image registration

We evaluated the effect of the image acquisition parameters on the accuracy of the principal axes and surface-fitting techniques for three-dimensional image registration. Using two types of phantom objects, MR brain image and a mathematically defined ellipsoid, we simulated pairs of scans with known acquisition parameters, including longitudinal coverage, magnitude of mis-registration, number of sections and section thickness. Both methods are sensitive to the systematic deformation of contours. The principal axes method is also sensitive to incomplete scan coverage and to the x-axis and y-axis misangulation. Both methods are insensitive to the number of sections, section thickness and the number of points per section. Surface fitting performed well without user supervision. There is no need for routine inclusion of the scaling factors as search parameters. The results confirm the feasibility of three-dimensional multimodality registration of brain scans with accuracy 1-2 mm, with surface fitting being the method of choice.