Perception of risk, feelings of vulnerability and effects on driving behaviour in women drivers across the lifespan.

Sustained driving in older age has implications for quality of life and mental health. Studies have shown that despite the recognised importance of driving in maintaining health and social engagement, many women give up driving prematurely or adopt self-imposed restrictive driving practices. Emotional responses to driving have been implicated in these decisions. This research examined the effect of risk perception and feelings of vulnerability on women’s driving behaviour across the lifespan. It also developed and tested a modified theory of planned behaviour intervention to positively affect driving habits. The first two studies (N=395) used quantitative analysis to model driving behaviours affected by risk perception and feelings of vulnerability, and established that feelings of vulnerability do indeed affect women’s driving behaviour, specifically resulting in increases in driving avoidance and the adoption of maladaptive driving styles. Further, that self-regulation, conceptualised as avoidance, is used by drivers across the lifespan. Qualitative analysis of focus group data (N=48) in the third study provided a deeper understanding of the variations in coping behaviours adopted by sub-groups of drivers and extended the definition of self-regulation to incorporate adaptive coping strategies. The next study (N=64) reported the construction and preliminary validation of the novel self-regulation index (SRI) to measure wider self-regulation behaviours using an objective measure of driving behaviour, a simulated driving task. The understanding gained from the formative research was used in the final study, an extended theory of planned behaviour intervention to promote wider self-regulation behaviour, measured using the previously validated self-regulation index. The intervention achieved moderate success with changes in affective attitude and normative beliefs as well as self-reported behaviour. The results offer promise for self-regulation, incorporating a spectrum of planning and coping behaviours, to be used as a mechanism to assist drivers in achieving their personal mobility goals whilst promoting safe driving.

A decade of silicone hydrogel development:surface properties, mechanical properties, and ocular compatibility

Since the initial launch of silicone hydrogel lenses, there has been a considerable broadening in the range of available commercial material properties. The very mobile silicon–oxygen bonds convey distinctive surface and mechanical properties on silicone hydrogels, in which advantages of enhanced oxygen permeability, reduced protein deposition, and modest frictional interaction are balanced by increased lipid and elastic response. There are now some 15 silicone hydrogel material variants available to practitioners; arguably, the changes that have taken place have been strongly influenced by feedback based on clinical experience. Water content is one of the most influential properties, and the decade has seen a progressive rise from lotrafilcon-A (24%) to efrofilcon-A (74%). Moduli have decreased over the same period from 1.4 to 0.3 MPa, but not solely as a result of changes in water content. Surface properties do not correlate directly with water content, and ingenious approaches have been used to achieve desirable improvements (e.g., greater lubricity and lower contact angle hysteresis). This is demonstrated by comparing the hysteresis value of the earliest (lotrafilcon-A, >40°) and most recent (delefilcon-A, <10°) coated silicone hydrogels. Although wettability is important, it is not of itself a good predictor of ocular response because this involves a much wider range of physicochemical and biochemical factors. The interference of the lens with ocular dynamics is complex leading separately to tissue–material interactions involving anterior and posterior lens surfaces. The biochemical consequences of these interactions may hold the key to a greater understanding of ocular incompatibility and end of day discomfort.

A study of the properties and applications of electrostatic charged particle oscillators

This investigation originated from work by Dr. A.H. McIlraith of the National Physical Laboratory who, in 1966, described a new type of charged particle oscillator. This makes use of two equal cylindrical electrodes to constrain the particles in such a way that they follow extremely long oscillatory paths between the electrodes under the influence of an electrostatic field alone. The object of this work has been to study the principle of the oscillator in detail and to investigate its properties and applications. Any device which is capable of creating long electron trajectories has potential application in the field of ultra high vacuum technology. It was therefore considered that a critical review of the problems associated with the production and measurement of ultra high vacuum was relevant in the initial stages of the work. The oscillator has been applied with a considerable degree of success as a high energy electrostatic ion source. This offers several advantages over existing ion sources. It can be operated at much lower pressures without the need of a magnetic field. The oscillator principle has also been applied as a thermionic ionization gauge and has been compared with other ionization gauges to pressures as low as 5 x 10- 11 torr.. This new gauge exhibited a number of advantages over most of the existing gauges. Finally the oscillator has been used in an evaporation ion pump and has exhibited fairly high pumping speeds for argon gas relative to those for nitrogen. This investigation supports the original work of Dr. A.H. McIlraith and shows that his proposed oscillator has considerable potential in the fields of vacuum technology and electron physics.

Anterior segment anomalies and effects on visual quality

The tear film, cornea and lens dictate the refractive power of the eye and the retinal image quality is principally defined by diffraction, whole eye wavefront error, scatter, and chromatic aberration. Diffraction and wave aberration are fundamentally pupil diameter dependent; however scatter can be induced by refractive surgery and in the normal ageing eye becomes an increasingly important factor defining retinal image quality. The component of visual quality most affected by the tear film, refractive surgery and multifocal contact and intraocular lenses is the wave aberration of the eye. This body of work demonstrates the effects of each of these anomalies on the visual quality of the eye. When assessing normal or borderline self-diagnosed dry eye subjects using aberrometry, combining lubricating eye drops and spray does not offer any benefit over individual products. However, subjects perceive a difference in comfort for all interventions after one hour. Total higher order aberrations increase after laser assisted sub-epithelial keratectomy performed using a solid-state laser on myopes, but this causes no significant decrease in contrast sensitivity or increase in glare disability. Mean sensitivity and reliability indices for perimetry were comparable to pre-surgery results. Multifocal contact lenses and intraocular lenses are designed to maximise vision when the patient is binocular, so any evaluation of the eyes individually is confounded by reduced individual visual acuity and visual quality. Different designs of aspheric multifocal contact lenses do not provide the same level of visual quality. Multifocal contact lenses adversely affect mean deviation values for perimetry and this should be considered when screening individuals with multifocal contact or intraocular lenses. Photographic image quality obtained through a multifocal contact or intraocular lens appears to be unchanged. Future work should evaluate the effect of these anomalies in combination; with the aim of providing the best visual quality possible and supplying normative data for screening purposes.

Novel b-lactams, their antibacterial and pharmacokinetic properties and pre-clinical evaluation

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Feelings of vulnerability and effects on driving behaviour:a qualitative study

Feelings of vulnerability in driving can be considered an emotional response to risk perception and the coping strategies adopted could have implications for continued mobility. In a series of focus groups with 48 licensed drivers aged 18-75 years, expressions of vulnerability in driver coping behaviours were examined. Despite feelings of vulnerability appearing low, qualitative thematic analysis revealed a complex array of coping strategies in everyday driving including planning, use of 'co-pilots', self-regulation, avoidance and confrontive coping, i.e. intentional aggression toward other road users. The findings inform future intervention studies to enable appropriate coping strategy selection and prolong independent mobility in older adults. © 2014 Elsevier Ltd. All rights reserved.

Nutrition of females during the peri-conceptional period and effects on foetal programming and health of offspring

The period around the time of conception is one characterised by considerable cytological and molecular restructuring as ovulation occurs, the oocyte is fertilised and the embryonic developmental programme begins. The intrinsic processes regulating peri-conceptional progression are supplemented by environmental factors, which contribute important metabolic information that influences several aspects of the developmental programme. Indeed, there is growing evidence from different mammalian animal models, reviewed here, that the peri-conceptional environment mediated through maternal nutrition can modify development throughout gestation and affect the physiological and metabolic health of adult offspring. The concept that adult disease risk may owe its origin to the quality of peri-conceptional maternal nutrition is one, which merits further research for mechanistic understanding and devising preventive strategies. © 2012 Elsevier B.V.

Surface roughness after excimer laser ablation using a PMMA model:profilometry and effects on vision

PURPOSE: To show that the limited quality of surfaces produced by one model of excimer laser systems can degrade visual performance with a polymethylmethacrylate (PMMA) model. METHODS: A range of lenses of different powers was ablated in PMMA sheets using five DOS-based Nidek EC-5000 laser systems (Nidek Technologies, Gamagori, Japan) from different clinics. Surface quality was objectively assessed using profilometry. Contrast sensitivity and visual acuity were measured through the lenses when their powers were neutralized with suitable spectacle trial lenses. RESULTS: Average surface roughness was found to increase with lens power, roughness values being higher for negative lenses than for positive lenses. Losses in visual contrast sensitivity and acuity measured in two subjects were found to follow a similar pattern. Findings are similar to those previously published with other excimer laser systems. CONCLUSIONS: Levels of surface roughness produced by some laser systems may be sufficient to degrade visual performance under some circumstances.

Enabling long journeys in electric vehicles:design and demonstration of an infrastructure location model

This research develops a methodology and model formulation which suggests locations for rapid chargers to help assist infrastructure development and enable greater battery electric vehicle (BEV) usage. The model considers the likely travel patterns of BEVs and their subsequent charging demands across a large road network, where no prior candidate site information is required. Using a GIS-based methodology, polygons are constructed which represent the charging demand zones for particular routes across a real-world road network. The use of polygons allows the maximum number of charging combinations to be considered whilst limiting the input intensity needed for the model. Further polygons are added to represent deviation possibilities, meaning that placement of charge points away from the shortest path is possible, given a penalty function. A validation of the model is carried out by assessing the expected demand at current rapid charging locations and comparing to recorded empirical usage data. Results suggest that the developed model provides a good approximation to real world observations, and that for the provision of charging, location matters. The model is also implemented where no prior candidate site information is required. As such, locations are chosen based on the weighted overlay between several different routes where BEV journeys may be expected. In doing so many locations, or types of locations, could be compared against one another and then analysed in relation to siting practicalities, such as cost, land permission and infrastructure availability. Results show that efficient facility location, given numerous siting possibilities across a large road network can be achieved. Slight improvements to the standard greedy adding technique are made by adding combination weightings which aim to reward important long distance routes that require more than one charge to complete.