Experimental measurement of a time-varying optical path difference by the small-aperture beam technique

We discuss the use of time series of the jitter angle of multiple, small-aperture probe beams (the small-aperture beam technique, or SABT) as they emerge from a turbulent, optically active flow-field to quantify the time-varying optical path difference (OPD). The flow field studied is that for the transitionally turbulent region of a two-dimensional heated jet. Techniques to construct a complete time series of instantaneous realizations of the OPD are first applied to a numerically generated flow field and then to an experimental flow field. The SABT sensor's measurement accuracy is assessed, and its application to flow fields that differ from the numerical heated jet is discussed.     

Test-retest reliability of Purdue Pegboard performance in thermoneutral and cold ambient conditions

In the cold, Purdue Pegboard (PP) performance declines. The purpose of this study was to determine if this cold-induced impairment is consistent across days (i.e. test-retest reliability) in 5°C. In thermoneutral air (25°C), 14 men were familiarised to the dominant hand (PPa) and bimanual (PPb) PP tasks. They then experienced two 90-min cold exposures (Day 1, Day 2) while wearing ～1 clo. Bare hands were maintained throughout. Performance on both tasks showed high reliability from day to day (intraclass correlations >0.700) in both thermoneutral and cold conditions. However for both tasks, room temperature performance did not predict performance in the cold (intraclass correlations <0.450). When screening applicants for manual labour in the cold, one must consider that room temperature dexterity does not correlate with dexterity in the cold. It is recommended that a 60-min period of cold exposure be employed to assess manual dexterity in these workers. STATEMENT OF RELEVANCE: This study shows that PP performance in room temperature does not predict performance in the cold but performance in the cold is consistent from day to day. When screening applicants for manual labour in the cold, it is recommended that dexterity tests be conducted in the same ambient conditions.     

Molecular recognition in the sphingosine 1-phosphate receptor family

Computational modeling and its application in ligand screening and ligand receptor interaction studies play important roles in structure-based drug design. A series of sphingosine 1-phosphate (S1P) receptor ligands with varying potencies and receptor selectivities were docked into homology models of the S1P(1-5) receptors. These studies provided molecular insights into pharmacological trends both across the receptor family as well as at single receptors. This study identifies ligand recognition features that generalize across the S1P receptor family, features unique to the S1P(4) and S1P(5) receptors, and suggests significant structural differences of the S1P(2) receptor. Docking results reveal a previously unknown sulfur-aromatic interaction between the S1P(4) C5.44 sulfur atom and the phenyl ring of benzimidazole as well as pi-pi interaction between F3.33 of S1P(1,4,5) and aromatic ligands. The findings not only confirm the importance of a cation-pi interaction between W4.64 and the ammonium of S1P at S1P(4) but also predict the same interaction at S1P(5). S1P receptor models are validated for pharmacophore development including database mining and new ligand discovery and serve as tools for ligand optimization to improve potency and selectivity.     

Ergonomic design of ticket barriers for use by the travelling public

This paper describes a two-stage study of the performance and acceptability of automatic ticket barriers. The aim of the research was to provide information to both manufacturers and transport operators to aid them in specifying equipment which would meet requirements for security and passenger flow and at the same time be acceptable, convenient and safe for use by passengers.

Stage one consisted of field studies at three railway stations and a laboratory evaluation of five types of ticket barrier. The field studies were undertaken to record and identify the characteristics of users and the type and frequency of problems they encountered. The laboratory trials consisted of objective and subjective evaluations of the four barriers by selected classes of user. Stage two consisted of a detailed study of certain features of barrier design, identified in stage one, including the type and speed of ticket checking, barrier dimensions and equipment for luggage handling. Results of the research have enabled design recommendations to be drawn up for use in the specification of future ticket barrier design.     

Powered domestic lawnmowers: design for safety

The paper describes a detailed accident investigation carried out by the Institute for Consumer Ergonomics for the Consumer Safety Unit at the Department of Trade. As such it serves to illustrate the application of two specific research techniques (i) analysis of product related accident data, and (ii) ergonomics evaluation of current models - and shows how these may be used to help in defining standards and criteria for the design of safer products. The study identified lawnmower features and activities associated with accidents recorded by the Home Accident Surveillance System. Ergonomics appraisal by expert assessment and user trials highlighted hazards associated with currently available powered lawnmowers. Performance criteria for safer design of selected features were developed with the aim of overcoming these hazards. At the end of the study liaison was sought with manufacturers to discuss how the results from the work could be used to effect.