Ability of dyslexic and control teenagers to sustain attention and inhibit responses

Dyslexia and attentional difficulty have often been linked, but little is known of the nature of the supposed attentional disorder. The Sustained Attention to Response Task (SART: Robertson, Manly, Andrade, Baddeley and Yiend, 1997) was designed as a measure of sustained attention and requires the withholding of responses to rare (one in nine) targets. To investigate the nature of the attentional disorder in dyslexia, this paper reports two studies which examined the performance of teenagers with dyslexia and their age-matched controls on the SART, the squiggle SART (a modification of the SART using novel and unlabellable stimuli rather than digits) and the go-gap-stop test of response inhibition (GGST). Teenagers with dyslexia made significantly more errors than controls on the original SART, but not the squiggle SART. There were no group differences on the GGST. After controlling for speed of reaction time in a sequential multiple regression predicting SART false alarms, false alarms on the GGST accounted for up to 22% extra variance in the control groups (although less on the squiggle SART) but negligible amounts of variance in the dyslexic groups. We interpret the results as reflecting a stimulus recognition automaticity deficit in dyslexia, rather than a sustained attention deficit. Furthermore, results suggest that response inhibition is an important component of performance on the standard SART when stimuli are recognised automatically.

Mechanisms of heat and mass transfer to and from single drops freely-suspended in an air stream

A specially-designed vertical wind tunnel was used to freely suspend individual liquid drops of 5 mm initial diameter to investigate drop dynamics, terminal velocity and heat and mass transfer rates. Droplets of distilled, de-ionised water, n-propanol, iso-butanol, monoethanolamine and heptane were studied over a temperature range of 50oC to 82oC. The effects of substances that may provide drop surface rigidity (e.g. surface active agents, binders and polymers) on mass transfer rates were investigated by doping distilled de-ionised water drops with sodium di-octyl sulfo-succinate surfactant. Mass transfer rates decreased with reduced drop oscillation as a result of surfactant addition, confirming the importance of droplet surface instability. Rigid naphthalene spheres and drops which formed a skin were also studied; the results confirmed the reduced transfer rates in the absence of drop fluidity. Following consideration of fundamental drop dynamics in air and experimental results from this study, a novel dimensionless group, the Oteng-Attakora, (OT), number was included in the mass transfer equation to account for droplet surface behaviour and for prediction of heat and mass transfer rates from single drops which exhibit surface instability at Re>=500. The OT number and the modified mass transfer equation are respectively: OT=(ava2/d).de1.5(d/) Sh = 2 + 0.02OT0.15Re0.88Sc0.33 Under all conditions drop terminal velocity increased linearly with the square root of drop diameter and the drag coefficient was 1. The data were correlated with a modified equation by Finlay as follows: CD=0.237.((Re/P0.13)1.55(1/We.P0.13) The relevance of the new model to practical evaporative spray processes is discussed.

An exploration of policies and practices used to showcase production facilities

Manufacturers who seek innovative ways in which to differentiate their products and services should not overlook the value of showcasing their production facilities. By careful design, visitors can be exposed to a series of experiences that can help to emphasize the value built into products. This topic has, however, received almost no attention by manufacturing researchers. Therefore, this paper describes a study of six manufacturers and, from this, proposes a set of guidelines for showcasing production facilities. Although exploratory, this work provides both a guide to manufacturers and a platform for more in-depth research. The guidelines and the case studies on which they are based are all described within the paper.

Social software in Higher Education:the diversity of applications and their contributions to students' learning experiences

Higher education institutions are increasingly using social software tools to support teaching and learning. Despite the fact that social software is often used in a social context, these applications can significantly contribute to the educational experience of a student. However, as the social software domain comprises a considerable diversity of tools, the respective tools can be expected to differ in the way they can contribute to teaching and learning. In this review on the educational use of social software, we systematically analyze and compare the diverse social software tools and identify their contributions to teaching and learning. By integrating established learning theory and the extant literature on the individual social software applications we seek to contribute to a theoretical foundation for social software use and the choice of tools. Case vignettes from several UK higher education institutions are used to illustrate the different applications of social software tools in teaching and learning.

A study of handedness and its relation to verbal and spatial ability

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

An examination of policies and issues relating to the management of industrial land in core and peripheral urban areas

DUE TO COPYRIGHT RESTRICTIONS ONLY AVAILABLE FOR CONSULTATION AT ASTON UNIVERSITY LIBRARY AND INFORMATION SERVICES WITH PRIOR ARRANGEMENT

Comparison of subjective and objective methods to determine the retinal arterio-venous ratio using fundus photography

Purpose: To assess the inter and intra observer variability of subjective grading of the retinal arterio-venous ratio (AVR) using a visual grading and to compare the subjectively derived grades to an objective method using a semi-automated computer program. Methods: Following intraocular pressure and blood pressure measurements all subjects underwent dilated fundus photography. 86 monochromatic retinal images with the optic nerve head centred (52 healthy volunteers) were obtained using a Zeiss FF450+ fundus camera. Arterio-venous ratios (AVR), central retinal artery equivalent (CRAE) and central retinal vein equivalent (CRVE) were calculated on three separate occasions by one single observer semi-automatically using the software VesselMap (ImedosSystems, Jena, Germany). Following the automated grading, three examiners graded the AVR visually on three separate occasions in order to assess their agreement. Results: Reproducibility of the semi-automatic parameters was excellent (ICCs: 0.97 (CRAE); 0.985 (CRVE) and 0.952 (AVR)). However, visual grading of AVR showed inter grader differences as well as discrepancies between subjectively derived and objectively calculated AVR (all p < 0.000001). Conclusion: Grader education and experience leads to inter-grader differences but more importantly, subjective grading is not capable to pick up subtle differences across healthy individuals and does not represent true AVR when compared with an objective assessment method. Technology advancements mean we no longer rely on opthalmoscopic evaluation but can capture and store fundus images with retinal cameras, enabling us to measure vessel calibre more accurately compared to visual estimation; hence it should be integrated in optometric practise for improved accuracy and reliability of clinical assessments of retinal vessel calibres. © 2014 Spanish General Council of Optometry.

Deconstructing phonological tasks:the contribution of stimulus and response type to the prediction of early decoding skills

Abstract Phonological tasks are highly predictive of reading development but their complexity obscures the underlying mechanisms driving this association. There are three key components hypothesised to drive the relationship between phonological tasks and reading; (a) the linguistic nature of the stimuli, (b) the phonological complexity of the stimuli, and (c) the production of a verbal response. We isolated the contribution of the stimulus and response components separately through the creation of latent variables to represent specially designed tasks that were matched for procedure. These tasks were administered to 570 6 to 7-year-old children along with standardised tests of regular word and non-word reading. A structural equation model, where tasks were grouped according to stimulus, revealed that the linguistic nature and the phonological complexity of the stimulus predicted unique variance in decoding, over and above matched comparison tasks without these components. An alternative model, grouped according to response mode, showed that the production of a verbal response was a unique predictor of decoding beyond matched tasks without a verbal response. In summary, we found that multiple factors contributed to reading development, supporting multivariate models over those that prioritize single factors. More broadly, we demonstrate the value of combining matched task designs with latent variable modelling to deconstruct the components of complex tasks.

An empirical examination of emotional and cognitive responses to threat appeals

Advertising and other forms of communications are often used by government bodies, non-government organisations, and other institutions to try to influence the population to either a) reduce some form of harmful behaviour (e.g. smoking, drunk- driving) or b) increase some more healthy behaviour (e.g. eating healthily). It is common for these messages to be predicated on the chances of some negative event occurring if the individual does not either a) stop the harmful behaviour, or b) start / increase the healthy behaviour. This design of communication is referred to by many names in the relevant literature, but for the purposes of this thesis, will be termed a ‘threat appeal’. Despite their widespread use in the public sphere, and concerted academic interest since the 1950s, the effectiveness of threat appeals in delivering their objective remains unclear in many ways. In a detailed, chronological and thematic examination of the literature, two assumptions are uncovered that have either been upheld despite little evidence to support them, or received limited attention at all, in the literature. Specifically, a) that threat appeal characteristics can be conflated with their intended responses, and b) that a threat appeal always and necessarily evokes a fear response in the subject. A detailed examination of these assumptions underpins this thesis. The intention is to take as a point of departure the equivocality of empirical results, and deliver a novel approach with the objective of reducing the confusion that is evident in existing work. More specifically, the present thesis frames cognitive and emotional responses to threat appeals as part of a decision about future behaviour. To further develop theory, a conceptual framework is presented that outlines the role of anticipated and anticipatory emotions, alongside subjective probabilities, elaboration and immediate visceral emotions, resultant from manipulation of the intrinsic message characteristics of a threat appeal (namely, message direction, message frame and graphic image). In doing so, the spectrum of relevant literature is surveyed, and used to develop a theoretical model which serves to integrate key strands of theory into a coherent model. In particular, the emotional and cognitive responses to the threat appeal manipulations are hypothesised to influence behaviour intentions and expectations pertaining to future behaviour. Using data from a randomised experiment with a sample of 681 participants, the conceptual model was tested using analysis of covariance. The results for the conceptual framework were encouraging overall, and also with regard to the individual hypotheses. In particular, empirical results showed clearly that emotional responses to the intrinsic message characteristics are not restricted to fear, and that different responses to threat appeals were clearly attributed to specific intrinsic message characteristics. In addition, the inclusion of anticipated emotions alongside cognitive appraisals in the framework generated interesting results. Specifically, immediate emotions did not influence key response variables related to future behaviour, in support of questioning the assumption of the prominent role of fear in the response process that is so prevalent in existing literature. The findings, theoretical and practical implications, limitations and directions for future research are discussed.

Effect of Cu and Sn promotion on the catalytic deoxygenation of model and algal lipids to fuel-like hydrocarbons over supported Ni catalysts

The ability of Cu and Sn to promote the performance of a 20% Ni/Al2O3 catalyst in the deoxygenation of lipids to fuel-like hydrocarbons was investigated using model triglyceride and fatty acid feeds, as well as algal lipids. In the semi-batch deoxygenation of tristearin at 260 °C a pronounced promotional effect was observed, a 20% Ni-5% Cu/Al2O3 catalyst affording both higher conversion (97%) and selectivity to C10-C17 alkanes (99%) in comparison with unpromoted 20% Ni/Al2O3 (27% conversion and 87% selectivity to C10-C17). In the same reaction at 350 °C, a 20% Ni-1% Sn/Al2O3 catalyst afforded the best results, giving yields of C10-C17 and C17 of 97% and 55%, respectively, which contrasts with the corresponding values of 87 and 21% obtained over 20% Ni/Al2O3. Equally encouraging results were obtained in the semi-batch deoxygenation of stearic acid at 300 °C, in which the 20% Ni-5% Cu/Al2O3 catalyst afforded the highest yields of C10-C17 and C17. Experiments were also conducted at 260 °C in a fixed bed reactor using triolein − a model unsaturated triglyceride − as the feed. While both 20% Ni/Al2O3 and 20% Ni-5% Cu/Al2O3 achieved quantitative yields of diesel-like hydrocarbons at all reaction times sampled, the Cu-promoted catalyst exhibited higher selectivity to longer chain hydrocarbons, a phenomenon which was also observed in experiments involving algal lipids as the feed. Characterization of fresh and spent catalysts indicates that Cu enhances the reducibility of Ni and suppresses both cracking reactions and coke-induced deactivation.

The influence of alexithymia and mood on eating psychopathology in a non-clinical female sample

It has been demonstrated that clinical and subclinical disor- dered eating are associated with elevated levels of depression and the personality trait alexithymia (ALX). ALX means literally lack of words for emotion and is associated with a difficulty identifying and describing feelings, and with an externally oriented cognitive style. The aim of the current study was to examine the inter-relationships between mood and ALX in accounting for variations in non-clinical eating psychopathology. 124 females were assessed on the 20- item Toronto Alexithymia Scale (TAS-20), the Hospital Anxiety and Depression Scale (HADS) and the Eating Disorders Inventory (EDI). Results revealed that EDI scores were positively associated with scores on the TAS-20 and with scores on the depression and anxi- ety subscales of the HADS. A series of stepwise multiple regressions revealed that depression and ALX accounted for 53% of the variance in total EDI scores and 40% of the variance in scores on the drive- for-thinness subscale of the EDI. Scores on the bulimia and body dissatisfaction subscales were predicted by the mood scores only. In conclusion, ALX and mood may contribute, alone and in combi- nation, to the development of some forms of disordered eating.