230 research outputs found
Involving users in OPAC interface design: Perspective from a UK study
This is the post-print versoin of the Article. The official published version can be accessed from the link below - Copyright @ 2007 SpringerThe purpose of this study was to determine user suggestions for a typical OPAC (Online Public Library Catalogue) application’s functionality and features. An experiment was undertaken to find out the type of interactions features that users prefer to have in an OPAC. The study revealed that regardless of users’ Information Technology (IT) backgrounds, their functionality expectations of OPACs are the same. However, based on users’ previous experiences with OPACs, their requirements with respect to specific features may change. Users should be involved early in the OPAC development cycle process in order to ensure usable and functional interface
Older and Younger Driver Performance at Complex Intersections: Implications for Using Perception-Response Time and Driving Simulation
Older drivers are at increased accident risk at intersections for a variety of maneuvers. To examine why, a study was conducted to assess older driver performance at complex intersections in a driving simulator. The University of Calgary Driving Simulator was used to test healthy older drivers (65-83, M = 71.4) and younger drivers (19-22, M = 20.7). Critical scenarios included the sudden appearance of a pedestrian in an intersection, a lastsecond yellow light, an unexpected change during a left, and a vehicle violating a stoplight. Older drivers had significantly higher perception response times (PRT) than younger drivers for the latter three of the four intersection scenarios. Analysis of specific maneuvers also revealed qualitative response differences between young and old groups. In contradiction to expectation, more older drivers ran the yellow light than younger drivers. The capability of older drivers to respond under time constraints is implicated. The utility of driving simulators to assess older driver performance at intersections was limited by the prevalence of simulator sickness
Older and Younger Driver Performance at Complex Intersections: Implications for Using Perception-Response Time and Driving Simulation
Older drivers are at increased accident risk at intersections for a variety of maneuvers. To examine why, a study was conducted to assess older driver performance at complex intersections in a driving simulator. The University of Calgary Driving Simulator was used to test healthy older drivers (65-83, M = 71.4) and younger drivers (19-22, M = 20.7). Critical scenarios included the sudden appearance of a pedestrian in an intersection, a lastsecond yellow light, an unexpected change during a left, and a vehicle violating a stoplight. Older drivers had significantly higher perception response times (PRT) than younger drivers for the latter three of the four intersection scenarios. Analysis of specific maneuvers also revealed qualitative response differences between young and old groups. In contradiction to expectation, more older drivers ran the yellow light than younger drivers. The capability of older drivers to respond under time constraints is implicated. The utility of driving simulators to assess older driver performance at intersections was limited by the prevalence of simulator sickness
Estimation of peptide concentration by a modified bicinchoninic acid assay
Although biuret based protein assays are theoretically applicable to peptide measurement, there is a high level of inter-peptide variation, determined largely by peptide hydrophobicity. This variation in peptide reactivity can be significantly reduced by heat-denaturation of peptides at 95 °C for 5 minutes in the presence of 0.1 M NaOH containing 1% (w/v) SDS, prior to incubation for 30 min at 37 °C in BCA standard working reagent. This modification to the standard bicinchoninic acid (BCA) assay protocol allows for an accurate, rapid and economical estimation of the peptide concentration within an unknown sample
Biodegradation kinetics of 4-fluorocinnamic acid by a consortium of Arthrobacter and Ralstonia strains
Arthrobacter sp. strain G1 is able to grow on 4-fluorocinnamic acid (4-FCA) as sole carbon source. The organism converts 4-FCA into 4-fluorobenzoic acid (4-FBA) and utilizes the two-carbon side-chain for growth with some formation of 4-fluoroacetophenone as a dead-end side product. We also have isolated Ralstonia sp. strain H1, an organism that degrades 4-FBA. A consortium of strains G1 and H1 degraded 4-FCA with Monod kinetics during growth in batch and continuous cultures. Specific growth rates of strain G1 and specific degradation rates of 4-FCA were observed to follow substrate inhibition kinetics, which could be modeled using the kinetic models of Haldane–Andrew and Luong–Levenspiel. The mixed culture showed complete mineralization of 4-FCA with quantitative release of fluoride, both in batch and continuous cultures. Steady-state chemostat cultures that were exposed to shock loadings of substrate responded with rapid degradation and returned to steady-state in 10–15 h, indicating that the mixed culture provided a robust system for continuous 4-FCA degradation
Structural studies of metal ligand complexes by ion mobility-mass spectrometry
The final publication is available at Springer via http://dx.doi.org/10.1007/s12127-013-0122-8Collision cross sections (CCS) have been measured for three salen ligands, and their complexes with copper and zinc using travelling-wave ion mobility-mass spectrometry (TWIMS) and drift tube ion mobility-mass spectrometry (DTIMS), allowing a comparative size evaluation of the ligands and complexes. CCS measurements using TWIMS were determined using peptide and TAAH calibration standards. TWIMS measurements gave significantly larger CCS than DTIMS in helium, by 9 % for TAAH standards and 3 % for peptide standards, indicating that the choice of calibration standards is important in ensuring the accuracy of TWIMS-derived CCS measurements. Repeatability data for TWIMS was obtained for inter- and intra-day studies with mean RSDs of 1. 1 % and 0. 7 %, respectively. The CCS data obtained from IM-MS measurements are compared to CCS values obtained via the projection approximation, the exact hard spheres method and the trajectory method from X-ray coordinates and modelled structures using density functional theory (DFT) based methods. © 2013 Springer-Verlag Berlin Heidelberg
Recommendations for reporting ion mobility mass spectrometry measurements
© 2019 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc. Here we present a guide to ion mobility mass spectrometry experiments, which covers both linear and nonlinear methods: what is measured, how the measurements are done, and how to report the results, including the uncertainties of mobility and collision cross section values. The guide aims to clarify some possibly confusing concepts, and the reporting recommendations should help researchers, authors and reviewers to contribute comprehensive reports, so that the ion mobility data can be reused more confidently. Starting from the concept of the definition of the measurand, we emphasize that (i) mobility values (K0) depend intrinsically on ion structure, the nature of the bath gas, temperature, and E/N; (ii) ion mobility does not measure molecular surfaces directly, but collision cross section (CCS) values are derived from mobility values using a physical model; (iii) methods relying on calibration are empirical (and thus may provide method-dependent results) only if the gas nature, temperature or E/N cannot match those of the primary method. Our analysis highlights the urgency of a community effort toward establishing primary standards and reference materials for ion mobility, and provides recommendations to do so. © 2019 The Authors. Mass Spectrometry Reviews Published by Wiley Periodicals, Inc
Collisional activation of ions in RF ion traps and ion guides: The effective ion temperature treatment
FAIMS operation for realistic gas flow profile and asymmetric waveforms including electronic noise and ripple
De Novo Truncating Mutations in WASF1 Cause Intellectual Disability with Seizures.
Next-generation sequencing has been invaluable in the elucidation of the genetic etiology of many subtypes of intellectual disability in recent years. Here, using exome sequencing and whole-genome sequencing, we identified three de novo truncating mutations in WAS protein family member 1 (WASF1) in five unrelated individuals with moderate to profound intellectual disability with autistic features and seizures. WASF1, also known as WAVE1, is part of the WAVE complex and acts as a mediator between Rac-GTPase and actin to induce actin polymerization. The three mutations connected by Matchmaker Exchange were c.1516C>T (p.Arg506Ter), which occurs in three unrelated individuals, c.1558C>T (p.Gln520Ter), and c.1482delinsGCCAGG (p.Ile494MetfsTer23). All three variants are predicted to partially or fully disrupt the C-terminal actin-binding WCA domain. Functional studies using fibroblast cells from two affected individuals with the c.1516C>T mutation showed a truncated WASF1 and a defect in actin remodeling. This study provides evidence that de novo heterozygous mutations in WASF1 cause a rare form of intellectual disability
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