Active and passive distraction using a head-mounted display helmet: Effects on cold pressor pain in children.

Objective: The current study tested the effectiveness of interactive versus passive distraction that was delivered via a virtual reality type head-mounted display helmet for children experiencing cold pressor pain. Design: Forty children, aged 5 to 13 years, underwent 1 or 2 baseline cold pressor trials followed by interactive distraction and passive distraction trials in counterbalanced order. Main Outcome Measures: Pain threshold and pain tolerance. Results: Children who experienced either passive or interactive distraction demonstrated significant improvements in both pain tolerance and pain threshold relative to their baseline scores. In contrast, children who underwent a second cold pressor trial without distraction showed no significant improvements in pain tolerance or threshold. Conclusion: Although both distraction conditions were effective, the interactive distraction condition was significantly more effective. Implications for the treatment of children's distress during painful medical procedures are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimental demonstration of composite-packet-switched WDM network

We propose and demonstrate experimentally a novel technique for packet switching on a ring network. We use the wavelength dimension to increase the transmission line rate and a novel packet-stacking technique to add/drop packets. Packet stacking is used for transport rate multiplication and for equal loading of wavelengths on the physical layer. Packet stacking, switching, and unstacking have been successfully demonstrated on a four-node hubbed ring network serving five source-destination pairs on four wavelengths. Each wavelength was running at 1-Gb/s bit rate.     

The respiratory gas exchange of sea turtle nests (Chelonia, Caretta)

Sea turtles lay about 100 leathery-shelled eggs in a 25 cm diameter chamber carefully excavated about 50 cm deep in a nesting beach, where the eggs exchange gases (at approximately 28 degrees C) during their 60-day incubation period. The sand surrounding the spherical nest chamber restricts the diffusion of gases into and out of the nest so that as embryonic development progresses, PO2 decreases and PCO2 increases in the gas inside the nest. PO2 falls to 80-100 torr and PCO2 rises to 40-60 torr inside 100-egg man-made Chelonia and Caretta nests. The change in gas tensions in the nest during development is very similar to that seen in the air cell of the chicken egg. Gas tensions inside the turtle nest and in the sand surrounding the nest can be described by a radial steady-state diffusion model. The rate of diffusion of gases in the sand is 30-50% of the rate found in the nest and 6-12% of the rate found in an equal volume of air. The sand surrounding the turtle nest appears to determine the gas exchange of the eggs in the nest and is functionally analogous to the shell surrounding the chicken embryo. The female sea turtle may construct her nest so as the maximize its gas exchange and minimize gas partial pressure gradients inside the nest.     

Teenage status of hyperactive and nonhyperactive learning disabled boys

Three groups of learning disabled boys--hyperactives, normoactives, and hypoactives--were studied in grade school, reevaluated at fourteen. At follow-up, all three groups remained at disadvantage to controls on academic and cognitive measures and on complex reaction time. Half the hyperactives had experienced major conflicts with authority, and over a third of hypoactives exhibited psychologically disturbing behaviors. Mental health of normoactives appeared comparable to controls.     

Computer Detection of Distortion in Arterial Pressure Signals

An application of the mathematical concept of curvature to the detection of distortion in arterial pressure signals is described. Curvature is defined and examples of digitally filtered pressure tracings show the relationship between curvature and the degree of damping. Even though curvature is also a function of the cardiovascular system producing the signal, the average sum of curvature can generally distinguish control signals from signals distorted by moderate amounts of blood or air in the catheter systems. Selected pressure signals with their associated sums of curvature show the properties and limitations of curvature for discriminating between the changes in the cardio-vascular system and distortion of pressure signals.     

Cognitive sex differences and mathematics and science achievement.

Comments on the original article "Sex Differences in Intrinsic Aptitude for Mathematics and Science?: A Critical Review," by E. S. Spelke (see record 2005-15840-001). Spelke considered "three claims that cognitive sex differences account for the differential representation of men and women in high-level careers in mathematics and science." The focus of this comment is on the claim regarding gender differences in mean levels of cognitive abilities. Spelke claimed (p. 954) that "most investigators of sex differences have concluded that males and females have equal cognitive ability, with somewhat different profiles." There are two major components to this comment. The first is mainly theoretical, and the second is both theoretical and empirical. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

我们来自何处，去向何方？——针对CAD 与BIM/LIM应用理论的比较研究

通过对文献进行比较性回顾,分析了数字化设计技术发展的2个关键转折期,以探索其共通的主题和平行的发展轨迹。第一个转折是将微型计算机引入消费市场,并随之在设计领域使用CAD软件;第二个转折是在更广泛的建筑信息模型(BIM)范围内纳入使用景观信息模型(LIM)。在数字技术和社会科学的框架内比较了2个时期对设计过程、生产率、人机关系、组织层级和设计创新的影响,同时以对景观设计公司人员的采访作为补充,帮助理解当代将BIM/LIM纳入景观设计实践的主要挑战。     

Development of a slurry injection technique for continuous fibre ultra-high temperature ceramic matrix composites

A simple and effective slurry injection method for producing dense and uniform ultra-high ceramic matrix composites from preforms of high fibre density was developed. As this method is based on slurry injection the homogeneity is not constrained to small preform sizes; dense components of high fibre volume can be produced in theoretically any size and shape. Samples produced by this method demonstrated high and consistent densities, with the injection method obtaining densities an average 27% higher and 87% lower in variability when compared to conventional vacuum impregnation. Tomography demonstrated no bias in the ceramic powder distribution for samples produced by injection, whereas samples produced by vacuum impregnation alone displayed poor powder penetration to the centre of large samples. The new approach yielded composites that were as strong and/or more consistent in strength compared to vacuum impregnation. Thermo-ablative testing demonstrated significant improvements in protective capability for materials produced by this route.     

Individual differences in skill learning: An integration of psychometric and information processing perspectives.

Reexamines the nature of individual differences in novel and practiced performance on skill learning tasks from an information processing framework. Two major sources of data and discussion are reanalyzed and critically evaluated. One source concerns the changes in interindividual between-subjects variability with task practice; the other pertains to associations between intellectual abilities and task performance during skill acquisition. Early studies yielded mixed results regarding the convergence or divergence of individual differences with practice. Other studies indicated small or trivial correlations between individual differences in intelligence and "gain" scores. More recent studies indicated small correlations between performance measures on skill learning tasks and standard intellectual and cognitive ability measures, as well as increasing amounts of task-specific variance over learning trials. Data confirm the proposition that individuals converge on performance as tasks become less dependent on attentional resources with practice. When appropriate methodological techniques are used and crucial task characteristics are taken into account, intellectual abilities play a substantial part in determining individual differences in skill learning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)