Biomechanics of chiasmal compression: Sensitivity of the mechanical behaviors of nerve fibers to variations in material property and geometry

The mechanism of bitemporal hemianopia is still unclear. Previous research suggested that the nerve fiber packing pattern may contribute to the selective damage of nasal (crossed) nerve fibers. Numerical models were built using finite element modeling to study the biomechanics of optic nerve fibers. The sensitivity of the mechanical behaviors of the nerve fibers to variations of five parameters in the nerve fiber model were investigated using design of experiments (DOE). Results show that the crossing angle is a very significant factor that affects a wide range of responses of the model. The strain difference between the crossed and the uncrossed nerve fibers may account for the phenomenon of bitemporal hemianopia. This work also highlights the need for more accurate material properties of the tissues in the model and an improved understanding of the microstructure of the optic chiasm.     

System Level Design for System on a Chip

We present the systems requirements generation and executable specification capture of a single chip LAN Adapter for communicating using the IEEE 1394 Serial Bus Protocol. The requirements generation starts with high level performance simulation and then passes to an executable specification suitable for implementation using a hardware/software co-design tool. The reuse of pre-existing components is supported, as well as synthesis of the system interface, but only after much work is done to program the hardware/software co-design tool. The actual design flow described allows feedback among all design levels, e.g. from implementation up to requirements, throughout the process.     

The pursuit of academic excellence and business engagement: is it irreconcilable?

Universities currently need to satisfy the demands of different audiences. In light of the increasing policy emphasis on “third mission” activities, universities are attempting to incorporate these into their traditional missions of teaching and research. University strategies to accomplishing its traditional missions are well-honed and routinized, but the incorporation of the third mission is posing important strategic and managerial challenges for universities. This study explores the relationship between university–business collaborations and academic excellence in order to examine the extent to which academic institutions can balance these objectives. Based on data from the UK Research Assessment Exercise 2001 at the level of the university department, we find no systematic positive or negative relationship between scientific excellence and engagement with industry. Across the disciplinary fields reported in the 2001 Research Assessment Exercise (i.e. engineering, hard sciences, biomedicine, social sciences and the humanities) the relationship between academic excellence and engagement with business is largely contingent on the institutional context of the university department. This paper adds to the growing body of literature on university engagement with business by examining this activity for the social sciences and the humanities. Our findings have important implications for the strategic management of university departments and for higher education policy related to measuring the performance of higher education research institutions.     

Stimulus-driven attentional capture by a static discontinuity between perceptual groups.

After C. L. Folk, R. W. Remington, and J. C. Johnston (1992) proposed their contingent-orienting hypothesis, there has been an ongoing debate over whether purely stimulus-driven attentional capture can occur for visual events that are salient by virtue of a distinctive static property (as opposed to a dynamic property such as abrupt onset). The present study identified 3 methodological criteria for establishing that attentional capture is stimulus driven and not contingent on top-down attentional control settings. In 5 experiments, attentional capture occurred for a static discontinuity at the boundary between one group of homogeneous items (red Xs) abutted next to a group of homogeneous items that were featurally different (green Xs) within a single row. Experiment 1 intentionally violated one of the criteria for demonstrating stimulus-driven capture so as to establish that contingent attentional capture can occur for this novel type of static cue. In the remaining 4 experiments, even with all 3 criteria for stimulus-driven capture partially or completely satisfied, the static discontinuity captured attention. These attentional capture effects are the first to be obtained when all 3 criteria for establishing that they are purely stimulus driven have been satisfied. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluating Pervasive and Ubiquitous Systems

Recognized evaluation strategies are essential to systematically advance a research field's state of the art. Pervasive and ubiquitous computing need such strategies to mature as a discipline and to enable researchers to objectively assess and compare new techniques' contributions. Researchers have shown that evaluating ubiquitous systems can be difficult, so approaches tend to be subjective, piecemeal, or both. To ensure that the validity and usability of proposed systems won't be compromised, researchers must reach consensus on a set of standard evaluation methods for ubiquitous systems. Otherwise, methods for scientifically testing and presenting state-of-the-art advances will remain unclear. In this article, the organizers from four different workshop series, each focused on this topic, summarize and discuss the main outcomes of these events.     

Hardness and low-temperature deformation of silica glass

Vickers diamond pyramid hardness measurements have been made on silica glass with varying thermal history using loads up to 1000 g. Hardness was independent of load and source. From interference photographs and subsequent anneal of the indentations at temperatures belowT _g, it was concluded that indentation leads primarily to densification of a volume of glass in the vicinity of the indenter. A portion of the densification which is recoverable at relatively low temperatures is attributed to molecular entanglement of the glassy network due to high pressure and shear. The other portion which is not recoverable belowT _g represents an approach to the final equilibrium density of the glass. Hardness of silica glass as determined by this method is thus defined as a resistance of the material to densification.This paper is based on part of a thesis submitted by J. E. Neely in partial fulfilment of the requirements for the degree of Master of Science in Materials Engineering, Rensselaer Polytechnic Institute, August 1967.     

Non-rectifying contacts to indium antimonide by immersion plating

Ohmic contacts to high resistivity indium antimonide have been made by displacement plating of copper. Some relevant facts regarding the plating process are presented.     

The new programming discipline

Recently there has been substantial interest in promoting ‘Structured Programming’ as a means of writing more nearly error free programs. However since the chief advocates of structured programming use ALGOL or PASCAL, and disdain FORTRAN, there is a difficulty in communication. Since it is my perception that structured programming and the lessons to be learned from proofs of correctness can be applied in any language, including FORTRAN, I feel that these ideas should be promulgated to applied scientific programmers. Hence this paper will commence with a summary of the whole complex of ideas and practices that are subsumed under the term ‘Structured Programming’. Then some simple examples of top down design and programming will be given. Finally I will return to a discussion of some of the problems which are likely to be encountered in the use and promulgation of structured programming.