SYSTEMS DEVELOPMENT: A DYING DISCIPLINE?

Examination of the three reasons offered for the decline of systems development—automation, delegation to users, and prepackaging—provides scant evidence that death is imminent.     

Visual function and cognitive aging: Differential role of contrast sensitivity in verbal versus spatial tasks.

Cognitive and sensory function are correlated in older adults. Sensory function may provide an index of neurological integrity (common-cause hypothesis). Declining sensory input may also directly impair cognition (direct-cause hypothesis). Accordingly, sensory function should more strongly predict cognitive performance and should account for more age-related variability in tasks with higher sensory demands. In a cross-sectional adult life span sample, visual contrast sensitivity was a better predictor and accounted for more of the age-related variability in high sensory-demand tasks, compared with low sensory-demand tasks, consistent with the direct-cause hypothesis. The results suggest a direct role for sensory function in cognitive aging when task conditions place heavy demands on sensory processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

CREATIVITY AND SOFTWARE DESIGN

Formal processes are increasingly recommended for those who build software. However, an analysis of the methods used by top software designers shows that cognitive, creative processes—in some ways the polar opposite of formal processes—are closer to the essence of the design task. Further analysis of the work of top designers exposes additional facts about design that challenge the traditional, textbook views. The implications of these findings to software builders are explored in this article.     

Dark time yellowing of white rigid vinyl outdoor weatherable compounds

White PVC siding which has been exposed to sunlight will after removal from the sunlight develop a darker color (yellow-brown). The longer this sample remains unexposed to sunlight the greater the color development. Testing has indicated that one or more photochemical mechanisms are occurring during this color development. A sample which appears yellow upon arrival at the home location after outside exposure can be re-whitened by re-exposing the sample to sunlight. Drastic color change will occur within a short period of time, usually less than 72 hours. This sample will have attained its white color with little or no yellowing visible when an original unexposed sample is held next to it. Testing conducted at an Arizona test site has confirmed these theories. Six months and one year weathered white siding samples, when measured at the test site, both experimental and commercial, showed that when the weathered samples are removed from the test racks and tristimulus values are measured daily, marked color changes occur rapidly. This paper addresses data which indicate that color development does occur but only in the very thin surface (5 to 10 micron layer) of the weathered samples. If these samples are washed and the abrasive action is sufficient to remove the surface layer, color development will no longer occur during non-exposure to sunlight.     

Real-time checkout: The ‘source error first’ approach

This paper proposes some improvements to the archaic methodologies currently used for checkout of real-time software. The emphasis is placed on removing errors from the computer program source code in the host computer environment, and deferring target computer checkout until those errors have been largely removed. Specific tools and techniques to make this possible are described. This improvement is seen to be risk-free and to reduce cost. It is, however, controversial.     

Temperature stabilization of ferrimagnetic resonance field in epitaxial YIG by Ga,La substitution

An impediment to the use of epitaxial YIG (yttrium iron garnet) in microwave devices has been the drift of the ferrimagnetic resonance field with temperature. This drift arises from the temperature sensitivity of the demagnetizing and anisotropy fields. By substituting Ga for some of the Fe and La for some of the Y in liquid phase epitaxial YIG, the demagnetizing and anisotropy field contributions to the drift were made self compensating. Temperature stability was thus achieved in perpendicular resonance. In parallel resonance there was a substantial reduction in drift.     

Search for new industrial oils. VII

Seed oils from 37 plant species in 18 families have been analyzed for fatty acid composition by the isomerization method. The variability encountered is evidenced by the range in content of component acids: from 0–23% for apparent linolenic acid, from 8–74% for apparent linoleic acid, and from 2–88% for apparent oleic acid. Dimorphecolic acid has been found to the extent of approximately 60% in a second species ofDimorphotheca, D. pluvialis (L.) Moench, and in the closely related species,Osteospermum ecklonis (DC.) T. Norl.O. spinescens Thunb. contained instead 30% of a conjugated triene, presumably the same as the 8,10,12-octadecatrienoic reported from the relatedCalendula officinalis L. Oils rich in monoenoic acids are mostly in the Umbelliferae and Araliaceae and presumably contain petroselinic acid as well as oleic. Presented at the AOCS meeting in St. Louis, Mo., May 1–3, 1961. A laboratory of the Northern Utilization Research and Development Division, Agricultural Research Service, U.S.D.A. Agricultural Research Service, U.S.D.A.