Showing papers by "Edinburgh Napier University published in 2009"

Development of in vitro systems for nanotoxicology : methodological considerations

Abstract: Due to the rapid development of a diverse array of nanoparticles, used in a wide variety of products, there are now many international activities to assess the potential toxicity of these materials. These particles are developed due to properties such as catalytic reactivity, high surface area, light emission properties, and others. Such properties have the potential to interfere in many well-established toxicity testing protocols. This article outlines some of the most frequently used assays to assess the cytotoxity and biological reactivity of nanoparticles in vitro. The article identifies key issues that need to be addressed in relation to inclusion of relevant controls, assessing particles for their ability to interfere in the assays, and using systematic approaches to prevent misinterpretation of data. The protocols discussed range from simple cytotoxicity assays, to measurement of reactive oxygen species and oxidative stress, activation of proinflammatory signaling, and finally genotoxicity. The aim of this review is to share knowledge relating to nanoparticle toxicity testing in order to provide advice and support for guidelines, regulatory bodies, and for scientists in general.

The water vapor sorption behavior of natural fibers.

Abstract: The water vapor sorption behavior of a range of natural fibers (jute, flax, coir, cotton, hemp, Sitka spruce) has been studied. The data were analyzed using the Hailwood Horrobin model for isotherm fitting and determi- nation of monolayer moisture content. The Hailwood Hor- robin model was found to provide good fits to the experimental data. The extent of hysteresis exhibited between the adsorption and desorption isotherms was de- pendent on fiber type studied and was larger with high lig- nin compared with low lignin content fibers. The area bounded by the hysteresis loop decreased as the isotherms were performed at progressively higher temperatures. This behavior is consistent with sorption interactions occurring with a glassy solid below the glass transition temperature. V C 2009 Wiley Periodicals, Inc. J Appl Polym Sci 112: 1524-1537, 2009

On the Complexity of Computing the Hypervolume Indicator

Abstract: The goal of multiobjective optimization is to find a set of best compromise solutions for typically conflicting objectives. Due to the complex nature of most real-life problems, only an approximation to such an optimal set can be obtained within reasonable (computing) time. To compare such approximations, and thereby the performance of multiobjective optimizers providing them, unary quality measures are usually applied. Among these, the hypervolume indicator (or S-metric) is of particular relevance due to its favorable properties. Moreover, this indicator has been successfully integrated into stochastic optimizers, such as evolutionary algorithms, where it serves as a guidance criterion for finding good approximations to the Pareto front. Recent results show that computing the hypervolume indicator can be seen as solving a specialized version of Klee's measure problem. In general, Klee's measure problem can be solved with O(n logn + nd/2logn) comparisons for an input instance of size n in d dimensions; as of this writing, it is unknown whether a lower bound higher than Omega(n log n) can be proven. In this paper, we derive a lower bound of Omega(n log n) for the complexity of computing the hypervolume indicator in any number of dimensions d > 1 by reducing the so-called uniformgap problem to it. For the 3-D case, we also present a matching upper bound of O(n log n) comparisons that is obtained by extending an algorithm for finding the maxima of a point set.

A comparison of nanoparticle and fine particle uptake by Daphnia magna.

Abstract: The use of nanoparticles in various applications is steadily on the rise, with use in a range of applications, including printer toner, sunscreen, medical imaging, and enhanced drug delivery. While research on human effects via, for example, inhalation is relatively well developed, the environmental assessment of nanoparticles is in its infancy. In the present study, we assessed the uptake and quantitative accumulation, as well as the depuration, of a model nanoparticle, a 20-nm fluorescent carboxylated polystyrene bead, in the aquatic invertebrate Daphnia magna and compared it to a larger, 1,000-nm particle. Using confocal microscopy, rapid accumulation in the gastrointestinal tract was observed within an hour of exposure to both particle sizes in both adults and neonates. Fluorescence could also be observed in the oil storage droplets, suggesting that both particle sizes have crossed the gut's epithelial barrier. Quantification of fluorescence of both sizes of particles showed that although uptake of the 20-nm particles was lower in terms of mass it was equal to or greater than 1000-nm particle uptake when expressed as surface area or particle number. Depuration was relatively rapid for the 1000-nm beads, decreasing by more than 90% over 4 h. In contrast, depuration of the 20-nm beads was less extensive, reaching 40% over 4 h. Transmission electron microscopy confirmed uptake of 1,000-nm beads, but uptake of 20-nm beads was inconclusive since similar-sized inclusions could be observed in control treatments.

Efficacy of simple short-term in vitro assays for predicting the potential of metal oxide nanoparticles to cause pulmonary inflammation.

Abstract: BackgroundThere has been concern regarding risks from inhalation exposure to nanoparticles (NPs). The large number of particles requiring testing means that alternative approaches to animal testing...

Identification of the mechanisms that drive the toxicity of TiO(2 )particulates: the contribution of physicochemical characteristics.

Abstract: This review focuses on outlining the toxicity of titanium dioxide (TiO2) particulates in vitro and in vivo, in order to understand their ability to detrimentally impact on human health. Evaluating the hazards associated with TiO2 particles is vital as it enables risk assessments to be conducted, by combining this information with knowledge on the likely exposure levels of humans. This review has concentrated on the toxicity of TiO2, due to the fact that the greatest number of studies by far have evaluated the toxicity of TiO2, in comparison to other metal oxide particulates. This derives from historical reasons (whereby the size dependency of particulate toxicity was first realised for TiO2) and due to its widespread application within consumer products (such as sunscreens). The pulmonary and dermal hazards of TiO2 have been a particular focus of the available studies, due to the past use of TiO2 as a (negative) control when assessing the pulmonary toxicity of particulates, and due to its incorporation within consumer products such as sunscreens. Mechanistic processes that are critical to TiO2 particulate toxicity will also be discussed and it is apparent that, in the main, the oxidant driven inflammatory, genotoxic and cytotoxic consequences associated with TiO2 exposure, are inherently linked, and are evident both in vivo and in vitro. The attributes of TiO2 that have been identified as being most likely to drive the observed toxicity include particle size (and therefore surface area), crystallinity (and photocatalytic activity), surface chemistry, and particle aggregation/agglomeration tendency. The experimental set up also influences toxicological outcomes, so that the species (or model) used, route of exposure, experiment duration, particle concentration and light conditions are all able to influence the findings of investigations. In addition, the applicability of the observed findings for particular TiO2 forms, to TiO2 particulates in general, requires consideration. At this time it is inappropriate to consider the findings for one TiO2 form as being representative for TiO2 particulates as a whole, due to the vast number of available TiO2 particulate forms and large variety of potential tissue and cell targets that may be affected by exposure. Thus emphasising that the physicochemical characteristics are fundamental to their toxicity.

Expert elicitation on ultrafine particles: likelihood of health effects and causal pathways

Abstract: Background Exposure to fine ambient particulate matter (PM) has consistently been associated with increased morbidity and mortality. The relationship between exposure to ultrafine particles (UFP) and health effects is less firmly established. If UFP cause health effects independently from coarser fractions, this could affect health impact assessment of air pollution, which would possibly lead to alternative policy options to be considered to reduce the disease burden of PM. Therefore, we organized an expert elicitation workshop to assess the evidence for a causal relationship between exposure to UFP and health endpoints.

Career Development of Expert Coaches

Abstract: Careers in coaching are a relatively new phenomenon in the UK and at present appear to be limited to the performance coach. This study, using an interview approach, examined the transition of expert coaches (n = 9) through various stages in their careers. The main aim of this study was to ascertain if expert coaches could explain the process of their development to perceived expert status. The interviewed coaches could offer no real insight into their designation as experts. They did raise some questions regarding the value of current coach education provision, especially as it related to their current role as coaches of elite athletes. Their methods of development were considered to be informal, with networking with other coaches of like mind believed to be essential to their progress. The ability to contextualise knowledge and information to suit both the individual and situation, as well as appropriate mentors at the initial stages of their coaching careers were also regarded as vital.

Assessing exposure, uptake and toxicity of silver and cerium dioxide nanoparticles from contaminated environments

Abstract: The aim of this project was to compare cerium oxide and silver particles of different sizes for their potential for uptake by aquatic species, human exposure via ingestion of contaminated food sources and to assess their resultant toxicity. The results demonstrate the potential for uptake of nano and larger particles by fish via the gastrointestinal tract, and by human intestinal epithelial cells, therefore suggesting that ingestion is a viable route of uptake into different organism types. A consistency was also shown in the sensitivity of aquatic, fish cell and human cell models to Ag and CeO2 particles of different sizes; with the observed sensitivity sequence from highest to lowest as: nano-Ag > micro Ag > nano CeO2 = micro CeO2. Such consistency suggests that further studies might allow extrapolation of results between different models and species.

Research Priorities to Advance Eco-Responsible Nanotechnology

Abstract: Manufactured nanomaterials (MNMs) are rapidly being incorporated into a wide variety of commercial products with significant potential for environmental release, which calls for eco-responsible design and disposal of nanoenabled products. Critical research needs to advance this urgent priority include (1) structure−activity relationships to predict functional stability and chemistry of MNMs in the environment and to discern properties that increase their bioavailability, bioaccumulation, and toxicity; (2) standardized protocols to assess MNM bioavailability, trophic transfer, and sublethal effects; and (3) validated multiphase fate and transport models that consider various release scenarios and predict the form and concentration of MNMs at the point of exposure. These efforts would greatly benefit from the development of robust analytical techniques to characterize and to track MNMs in the environment and to validate models and from shared reference MNM libraries.

Emotional journeys: young people and transitions to university

Abstract: This paper offers an interpretation of the role of emotions in understanding the transitions that young people make to university. I draw on qualitative research with a group of non‐traditional students, entering elite universities, to argue that youth transitions are emotional as well instrumental affairs. I argue that choice‐making processes incorporate both trust in, and fear of, the transitions infrastructure, and that these emotions infuse more instrumental judgements about the economic benefits of higher education. I also demonstrate that emotional aspects of class – including feelings of entitlement to education and the rejection of normative student identities – constitute the experience of ‘being’ or ‘doing’ a student. A broader understanding of how young people become university students then depends not just on developing a new identity but on the complex interaction between emotion and infrastructure.

Smoking restrictions in the home and secondhand smoke exposure among primary schoolchildren before and after introduction of the Scottish smoke-free legislation

Abstract: Objective: To examine change in home smoking restrictions one year after introduction of Scottish smoke-free legislation, and whether type of restriction impacts upon secondhand smoke (SHS) exposure among children. Design: Comparison of nationally representative, cross-sectional, class-based surveys carried out in the same schools before and after legislation. Participants: 2527 primary schoolchildren (aged around 11 years) surveyed in January 2006 and 2379 in January 2007. Outcome measures: Self-reported home smoking restrictions, salivary cotinine concentrations. Results: Children surveyed after implementation of legislation were more likely than those surveyed before its introduction to report complete home smoking restrictions as opposed to partial (relative risk ratio (partial vs complete) 0.75 (95% CI 0.63 to 0.89) or no restrictions (RR (no restrictions vs complete) 0.50 (0.40 to 0.63). Children living with smokers were less likely to have stringent restrictions in place compared with children living with non-smokers (for both vs neither parents smoke: RR (partial vs complete) 18.29 (13.26 to 25.22) and RR (no restrictions vs complete) 104.73 (70.61 to 155.33). Among smoking households, restriction type varied according to the number and gender of parents who smoke. In both smoking and non-smoking households, children’s SHS exposure was directly related to type of home smoking restriction, with lowest exposures among those reporting complete restrictions. Conclusion: This study has shown an increase in the proportion of children reporting a complete ban on smoking in their household after the introduction of smoke-free legislation and supports growing evidence of the wider impact smoke-free legislation can have on smoker behaviour. However, quitting smoking combined with complete home smoking bans will still afford children the best protection from SHS exposure.

Corporate risk disclosure by UK firms: trends and determinants

Abstract: This study explores risk disclosure practice using content analysis of 156 annual reports prepared by 52 UK listed companies in three different periods (1998, 2001 and 2004). The study relates the extent of risk disclosure to firm-specific characteristics. The study found, a trend of increasing amounts of risk disclosure in the annual report over the six-year period influenced by accounting regulation and accounting institutes' recommendations. US dual listing and involvement in heavy industry are significantly and positively correlated with the level of risk information disclosed by the sampled companies. Risk disclosure is not related to size or leverage.

Toll-like receptor expression on classic and pro-inflammatory blood monocytes after acute exercise in humans

Abstract: Monocytes are a heterogeneous group of cells, the relative distribution of which change in peripheral blood following a strenuous bout of aerobic exercise. Monocyte subtypes can be identified in blood based on the cell surface expression of CD14 and CD16: classic (CD14(++bright)/CD16(-negative)) and the CD16(+dim) (CD14(++bright)/CD16(+dim)) and CD16(++bright) (CD14(+dim)/CD16(++bright)) pro-inflammatory subtypes. Whole monocyte population changes in TLR2, TLR4 and HLA.DR expression have previously been documented after acute exercise without accounting for relative changes in monocyte subpopulations, therefore, this study examined their expression on classic and pro-inflammatory monocyte subsets following 45min of treadmill running at 75% VO(2max). Mononuclear cells isolated from the peripheral blood of moderately trained male subjects (n=15) before (PRE), immediately after (POST) and 1h after (1H) exercise were assessed for TLR2, TLR4 and HLA.DR expression on blood monocytes and their subpopulations using three-colour flow cytometry. Compared to PRE, the proportion of CD14+/CD16+ monocytes was 27% greater POST and 49% less at 1H and was associated with changes in the CD16(++bright) pro-inflammatory subtype (p 0.05). We conclude that acute exercise causes localised changes in TLR2, TLR4 and HLA.DR expression within specific blood monocyte subpopulations, and could therefore be occurring at the cellular level. Such alterations might have significant implications for modulation of post-exercise immune surveillance.

Project selection and its impact on the successful deployment of Six Sigma

Abstract: Purpose – The purpose of this paper is to focus on the importance of the project selection process and its role in the successful deployment of Six Sigma within organizations. Design/methodology/approach – A review of the literature is presented, highlighting the importance of project selection in Six Sigma deployment, which is an area of extreme importance that has been less researched in the past. The paper, through a real-life case study, proposes a hybrid methodology, which combines the analytical hierarchy process and the project desirability matrix to select a project for Six Sigma deployment. Findings – The paper demonstrates the efficacy of proposed methodology by its application in a small and medium-sized enterprise (SME) manufacturing die-casting product. The example provided is a real-life case study conducted by the authors in an organization embracing the Six Sigma business strategy within their day-to-day functioning. Research limitations/implications – The proposed methodology is tested only in a case study SME, which is the limitation of the paper. The robustness of the methodology can be tested by conducting several case studies in organizations and comparing the results with other existing methodologies for project selection such as project prioritisation matrix or the failure mode and effect analysis. Practical implications – The paper accentuates the importance of the project selection process for Six Sigma deployment, which can have a tremendous effect on the business profitability of an organization. The paper is relevant to both industry practitioners and researchers. Originality/value – The paper presents a methodology linking the project selection process to successful deployment of Six Sigma within organizations, an important topic that has been neglected in the past. The paper will enable managers and practitioners to emphasize the importance of project selection and to identify and focus on the critical success factors in successful deployment of Six Sigma projects.

When are summary ROC curves appropriate for diagnostic meta‐analyses?

Abstract: Diagnostic tests are increasingly evaluated with systematic reviews and this has lead to the recent developments of statistical methods to analyse such data. The most commonly used method is the summary receiver operating characteristic (SROC) curve, which can be fitted with a non-linear bivariate random-effects model. This paper focuses on the practical problems of interpreting and presenting data from such analyses. First, many meta-analyses may be underpowered to obtain reliable estimates of the SROC parameters. Second, the SROC model may be inappropriate. In these situations, a summary with two univariate meta-analyses of the true and false positive rates (TPRs and FPRs) may be more appropriate. We characterize the type of problems that can occur in fitting these models and present an algorithm to guide the analyst of such studies, with illustrations from analyses of published data. A set of R functions, freely available to perform these analyses, can be downloaded from (www.diagmeta.info).

Triangulation in practice

Abstract: Triangulation is the means by which an alternate perspective is used to validate, challenge or extend existing findings. It is frequently used when the field of study is difficult, demanding or contentious and presence research meets all of these criteria. We distinguish between the use of hard and soft triangulation—the former emphasising the challenging of findings, the latter being more confirmatory in character. Having reviewed a substantial number of presence papers, we conclude that strong triangulation is not widely used while soft triangulation is routinely employed. We demonstrate the usefulness of hard triangulation by contrasting an ontological analysis of in-ness with an empirical study of (computer) game playing. We conclude that presence research would be well served by the wider use of hard triangulation and for the reporting of anomalous and ill-fitting results.

Children with cerebral palsy: severity and trends over time

Abstract: Increasingly, more very-low-birthweight infants in the developed world are now expected to survive the neonatal period than was previously the case. There are concerns that there may be a related increase in the number of infants developing severe sensorimotor impairments. Pooled data from five registers contributing to the UK Network of Cerebral Palsy Registers, Surveys and Databases were used to identify patterns of motor impairment in relation to additional impairments and to birthweight, and to assess whether prevalence of cerebral palsy (CP) by birthweight and by severity of motor impairment had changed over time. Low-birthweight infants are at greater risk of developing CP than larger-birthweight babies. The CP rate amongst children with birthweights = 2500 g, 23% compared with 15% weighing < 1000 g (P < 0.001) were in the most severely motor impaired group. Severe motor impairment is associated with higher levels of additional impairments. CP rates for each motor impairment group in the 1990s were similar to those in the late 1970s. Rates of CP among infants born below normal birthweight are high but have decreased over time. The CP rate for infants weighing 1000-1499 g at birth decreased from around 180 per 1000 livebirths in 1979 to around 50 per 1000 livebirths from the early 1990s onwards.

Global brand market‐entry strategy to manage corporate reputation

Abstract: Purpose – This paper aims to present a case for the practical management of corporate reputation, in relation to two groups of concepts: communication, identity, and trust; and communication, identity, and image.Design/methodology/approach – A review of the current knowledge of corporate reputation, personality, identity, and image leads to development of a strategy framework to enhance/protect corporate reputation. A case study involving a corporate logo introduced into a developed market by an emerging multinational corporation (EMNC) is presented.Findings – The paper identifies that credibility and trust are significant elements which must be managed and communicated to maintain the firm's corporate image and reputation.Originality/value – A conceptual model is presented illustrating a series of internal and external factors affecting communication and trust, which influence the customer and assist in shaping corporate reputation. The case of the EMNC Chinese corporation Haier to introduce its brand in...

Writing about listening: alternative discourses in rock journalism

Abstract: ‘Alternative’ publications challenge the conventional discourses of rock journalism. In particular, the dominant discourses of authenticity, masculinity and mythology might be countered by publications that emphasise historical and (sub)cultural framing, and that present radicalised ‘spaces of listening.’ Using Bourdieu’s field theory to identify autonomous and semi-autonomous sites for rock criticism, the paper compares how a fanzine (the Sound Projector) and what Frith has termed an ideological magazine (the Wire) construct their reviews. The findings suggest that, whilst there is no evidence for an absolute break with the dominant conventions of reviewing, there is a remarkable polyglottism in alternative music reviewing. The paper emphasises differing cultural and social practices in the multiple ways the publications write about music, and argues for the value of such polyglottism.