Head-mounted spatial instruments II: Synthetic reality or impossible dream

A spatial instrument is defined as a spatial display which has been either geometrically or symbolically enhanced to enable a user to accomplish a particular task. Research conducted over the past several years on 3-D spatial instruments has shown that perspective displays, even when viewed from the correct viewpoint, are subject to systematic viewer biases. These biases interfere with correct spatial judgements of the presented pictorial information. The design of spatial instruments may not only require the introduction of compensatory distortions to remove the naturally occurring biases but also may significantly benefit from the introduction of artificial distortions which enhance performance. However, these image manipulations can cause a loss of visual-vestibular coordination and induce motion sickness. Consequently, the design of head-mounted spatial instruments will require an understanding of the tolerable limits of visual-vestibular discord

Confocal Microscopy: a Powerful Tool for Biological Research

Conventional light microscopy allows the observation of living as well as fixed cells and tissues to generate two-dimensional images. The out-of-focus information often obscures the ultrastructural details, especially in thick specimens with overlapping structures. The earliest available light microscopy visualized the objects in hydrated state in two-dimensions during their temporal development. The emergence of electron microscopy (EM) provided superb resolution of ultrastructural details, but it was applicable only for objects in the dehydrated state and thereby potentially introducing handling artifacts. The usefulness of optical methods, however, has been limited by the poor depth discrimination. Often, the fluorescence and reflectance images are severely degraded by the scattered- or emitted-light from tissue structures outside the plane of focus. These limitations have been partially overcome by video image processing and deconvolution. Laser scanning confocal microscopy (LSCM) overcomes the above difficulties and produces improved light microscopic images of fixed as well as living cells and tissues. In terms of resolution of the image, the confocal microscope occupies a position in between the light and electron microscopes. Confocal microscope generates information from a well-defined optical section rather than from the entire specimen, thereby eliminating the out-of-focus glare and increasing the contrast, clarity and detection sensitivity. Optical sectioning is noninvasive and less time consuming compared to reconstruction algorithms to give 3-D images. Optical sectioning is achieved not only in the xy plane (perpendicular to the optical axis of the microscope) but also vertically in the xz or yz plane (parallel to the optical axis). With vertical sectioning, cells are scanned laterally (x or y axis) as well as in depth (z axis). Stacks of optical sections taken at successive focal plane (known as z series) are then reconstructed to generate a 3-D version of the specimen. The 3-D image can be directly visualized where each data point represents the quantity of specific contrast parameter used at a certain point in space. The image processing can be additionally used to enhance the confocal images. It is widely used in the fluorescence mode for different specimens and in bright field reflection mode for objects of different forms

Aerospace medicine and biology: A cumulative index to a continuing bibliography (supplement 345)

This publication is a cumulative index to the abstracts contained in Supplements 333 through 344 of Aerospace Medicine and Biology: A Continuing Bibliography. Seven indexes are included -- subject, personal author, corporate source, foreign technology, contract number, report number, and accession number

Special Libraries, Spring 1995

Volume 86, Issue 2https://scholarworks.sjsu.edu/sla_sl_1995/1001/thumbnail.jp

1994-1995

Contains information on courses and class descriptions as well as campus resources at Collin College.https://digitalcommons.collin.edu/catalogs/1006/thumbnail.jp

Academic catalog 2016-2018

Midlands Technical College publishes an annual academic catalog with information for students about procedures, academic programs, and course descriptions