Assessment of conformational parameters as predictors of limited proteolytic sites in native protein structures

Despite the importance of limited proteolysis in biological systems it isoften difficult to rationalize why a proteinase hydrolyses a particularbond, given a simple sequence specificity alone. Understanding of thestructural properties limiting the proteolysis represents a first step onthe pathway to control and manipulation of this phenomena. An expanded setof nick-sites in proteins of known tertiary structure, cut by both narrowand broad specificity proteinases, has been generated yielding a robustdata set of strictly limited sites. A critical evaluation of an expandedset of conformational parameters revealed a strong correlation with limitedproteolytic sites, although they are only modest predictors in isolation.The overall predictive power is significantly improved when theconformational parameters are combined in a weighted predictive scheme thatpermits their relative importance to be compared via a Metropolis searchprotocol. A subset of the parameters performs equally well demonstratingthe key determinants of susceptibility. The derived predictive algorithmhas been made available via the internet. Its utility for predicting othersurface-correlated features is also discussed.     

Mast cell and basophil development

In human esophageal cancers, no ras gene mutations but a relatively high prevalence of p53 gene mutations have been reported. We found a high prevalence of point mutations in Ha-ras and p53 genes in N-nitrosomethylbenzylamine (NMBA)-induced esophageal tumors in two strains of rats (BD VI and F344). Our analysis showed the point mutation GGA-->GAA (expected from the known mechanisms of action of NMBA) at Ha-ras codon 12 in 22 of 46 (48%) and 22 of 38 (58%) papillomas from BD VI and F344 rats, respectively. There was no significant difference in the prevalence of ras mutations in tumors induced by high doses (5.0 mg/kg) and low doses (2.5 mg/kg) of NMBA. Eleven papillomas from each strain were analyzed for p53 mutations. The prevalent mutations found were G-->A and C-->T transitions. The frequency of p53 mutation was 36% (four of 11) for each strain. No apparent hot-spot codon or exon was found in the p53 gene, and two papillomas contained double mutations in this gene. The high prevalence of G-->A mutations in the rat Ha-ras gene contrasts with that in the human gene, in which no ras mutations have been found in primary tumors, and suggests either that the biology of esophageal carcinogenesis differs in humans and rats or that nitrosamines are not the major etiological risk factor for human esophageal cancers.     

Sensitive ground-fault relaying

Sensitive ground-fault protection refers to the concept of detecting low levels of ground-fault current that might cause electrocution of any human that becomes part of the ground-current path and providing warnings. The concepts behind sensitive ground-fault relaying for use on AC and DC low-voltage utilization systems are covered. The background for these relaying types is presented, and it is shown that the critical component in sensitive ground-fault relay design is the current sensor. Zero-sequence devices for three-phase industrial utilization systems and a saturable-transformer device for DC utilization are discussed. Relaying schemes for both AC and DC systems are presented. This study is aimed at mine power systems but could be applicable to any portable low-voltage portion of industrial power systems that involve handling by personnel     

The Synchronous Approach to Designing Reactive Systems

Synchronous programming is available through several formally defined languages having very different characteristics: Esterel is imperative, while Lustre and Signal are declarative in style; Statecharts and Argos are graphical languages that allow one to program by constructing hierarchical automata. Our motivation for taking the synchronous design paradigm further, integrating imperative, declarative (or dataflow), and graphical programming styles, is that real systems typically have components that match each of these profiles. This paper motivates our interest in the mixed language programming of embedded software around a number of examples, and sketches the semantical foundation of the Synchronie toolset which ensures a coherent computational model. This toolset supports a design trajectory that incorporates rapid prototyping and systematic testing for early design validation, an object oriented development methodology for long term software management, and formal verification at the level of automatically generated object code.     

Auditory navigation in hyperspace: design and evaluation of a non-visual hypermedia system for blind users

This paper presents the design and evaluation of a hypermedia system for blind users, making use of a nonvisual interface, non-speech sounds, three input devices, and a 37 node hypermedia module. The important components of an effective auditory interface are discussed, together with the design of the auditory interface to hypermedia material. The evaluation, which was conducted over several weeks and used a range of complementary objective and subjective measures to assess users' performance and preferences, is described. The findings from the evaluation with nine visually impaired student participants are presented. The results from this research can be applied to the design and evaluation of other non-visual hypermedia systems, such as auditory World Wide Web (WWW) browsers and digital talking books.     

Linguistic and location effects in compliance with pesticide warning labels for amateur and professional users

Three studies explored amateur and professional users' compliance with pesticide warning labels. Professionals were classified as people working in a profession in which the use of pesticides is a necessary part of their job. Amateurs used pesticides only in their leisure time. The first study showed that the wording used affected perception of the appropriateness of hazard statements, one of the most effective variations being the use of the personal pronoun (statements beginning "You should..."). The location of warning information was also found to affect actual compliance: Compliance increased when warning information was presented in the directions for use section. A supplemental directive increased compliance only for professional users. In a final study, "best-case" and "worst-case" linguistic variations were combined with best-case and worst-case locations for safety information. Instruction statements using the personal pronoun and presented in the directions for use section resulted in the highest levels of compliance. The differences in compliance between amateur and professional users are interpreted within the framework of Rasmussen's (1986) distinction among skill-, rule-, and knowledge-based behavior. Actual or potential applications of this research include the design of warning labels and safety information.     

FraRI: an algorithm to account for the discontinuity at 60° N in MODIS temperature products

The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA's Terra and Aqua satellites conducts continuous monitoring of the Earth's land surface and oceans. Recently, a sharp discontinuity (averaging 1.9°C) has been noticed at 60° N in both MODIS daytime and night-time land surface temperature (LST) products. This linear artefact arises because the CO₂ high cloud test in the operational code for the generation of the MODIS cloud mask product is used only in the non-polar region (between 60° N and 60° S). The resulting discontinuity clearly has negative implications for any statistical applications of these temperature data. In this technical note we present a new algorithm, which minimizes this discontinuity. The method uses edge detection and elimination based on a mixture of Sobel and non-linear Laplacian filters (edge detection and quantification), cubic splines (edge modelling), and a controllable power function for image restoration. The implementation of this algorithm is demonstrated on an image of average minimum night-time LST between 2001 and 2008.     

Fortran computer program for inextensional bending of a doubly curved shell triangular element

A Fortran computer program is described which calculates physical quantities for a class of shell triangular elements undergoing inextensional bending. These elements are in quadratic parametric representation and may have positive, zero or negative Gaussian curvature. The exact inextensional bending solutions for the rectangular displacement components are cubic in the surface co-ordinates and the curvature changes are relatively slowly varying.