Tear and skin phospholipids:analysis and hydrogel analogues

This thesis is concerned with the analysis of phospholipids in the tear film and with the synthesis of phospholipids analogous to hydrogels. The work consists of two areas. The first area is the study of the phospholipids in the tear film, their nature and fate. The use of liquid chromatography mass spectrometry determined that the concentration of phospholipids in the tear film was less than previously thought. The analysis of the tear film phospholipids continued with thin layer chromatography. This showed the presence of diacylglycerides (DAGs) in the tear film at relatively high concentrations. The activity of an enzyme, phospholipase C, was found in the tear film. It was hypothesised that the low concentration of phospholipids and high concentrations of DAG in the tear film was due to the action of this enzyme. The second area of study was the synthesis of phospholipids analogous materials for use in ocular and dermal applications for use in ocular and dermal applications.For ocular applications the synthesis involved the use of the monomer N,N-dimethyl-N-(2-acryloylethyl)-N-(3-sulfopropyl) ammonium betaine (SPDA) in combination with 2-hdyroxyethyl methacrylate (HEMA). Charge-balanced membranes were also synthesised using potentially anionic monomers in conjunction with cationic monomers in stoichiometrically equivalent ratios also with HEMA as a commoner. Membranes of SPDA copolymers and charge-balanced copolymers proved to have some properties suitable for ocular applications. The dermal materials consisted of one family of partially hydrated hydrogels synthesised from SPDA in combination with ionic monomers: sodium 2-(acrylamido)-2-methyl propane sulfonate and acrylic acid-bis(3-sulfopropyl)-ester, potassium salt. A second family of partially hydrated hydrogels was synthesised from N-vinyl pyrrolidone in combination with the same ionic monomers. Both of the partially hydrated hydrogels synthesised proved to have some properties suitable for use as adhesives for the skin.

Introduction: the media, animal conservation and environmental education

Natural History filmmaking has a long history but the generic boundaries between it and environmental and conservation filmmaking are blurred. Nature, environment and animal imagery has been a mainstay of television, campaigning organisations and conservation bodies from Greenpeace to the Sierra Club, with vibrant images being used effectively on posters, leaflets and postcards, and in coffee table books, media releases, short films and viral emails to educate and inform the general public. However, critics suggest that wildlife film and photography frequently convey a false image of the state of the world’s flora and fauna. The environmental educator David Orr once remarked that all education is environmental education, and it is possible to see all image-based communication in the same way. The Media, Animal Conservation and Environmental Education has contributions from filmmakers, photographers, researchers and academics from across the globe. It explores the various ways in which film, television and video are, and can be, used by conservationists and educators to encourage both a greater awareness of environmental and conservation issues, and practical action designed to help endangered species. This book is based on a special issue of the journal Environmental Education Research.

The media, animal conservation and environmental education

Natural History filmmaking has a long history but the generic boundaries between it and environmental and conservation filmmaking are blurred. Nature, environment and animal imagery has been a mainstay of television, campaigning organisations and conservation bodies from Greenpeace to the Sierra Club, with vibrant images being used effectively on posters, leaflets and postcards, and in coffee table books, media releases, short films and viral emails to educate and inform the general public. However, critics suggest that wildlife film and photography frequently convey a false image of the state of the world’s flora and fauna. The environmental educator David Orr once remarked that all education is environmental education, and it is possible to see all image-based communication in the same way. The Media, Animal Conservation and Environmental Education has contributions from filmmakers, photographers, researchers and academics from across the globe. It explores the various ways in which film, television and video are, and can be, used by conservationists and educators to encourage both a greater awareness of environmental and conservation issues, and practical action designed to help endangered species. This book is based on a special issue of the journal Environmental Education Research.

Critical practice and the public pedagogy of environmental and conservation media

Natural History filmmaking has a long history but the generic boundaries between it and environmental and conservation filmmaking are blurred. Nature, environment and animal imagery has been a mainstay of television, campaigning organisations and conservation bodies from Greenpeace to the Sierra Club, with vibrant images being used effectively on posters, leaflets and postcards, and in coffee table books, media releases, short films and viral emails to educate and inform the general public. However, critics suggest that wildlife film and photography frequently convey a false image of the state of the world’s flora and fauna. The environmental educator David Orr once remarked that all education is environmental education, and it is possible to see all image-based communication in the same way. The Media, Animal Conservation and Environmental Education has contributions from filmmakers, photographers, researchers and academics from across the globe. It explores the various ways in which film, television and video are, and can be, used by conservationists and educators to encourage both a greater awareness of environmental and conservation issues, and practical action designed to help endangered species. This book is based on a special issue of the journal Environmental Education Research.

Metaphor in translation:possibilities for process research

This paper explores potential benefits of closer interaction between metaphor studies and translation process research. It presents some developments within Translation Studies which make use of conceptual metaphor theory and illustrates some process research methods for investigating metaphors. The paper considers a number of methodological recommendations and argues that of greatest importance is the need to take full account of insights from metaphor studies and associated disciplines. Another important potential innovation is the use of a multilingual approach in respect of both product- and process-oriented studies in order to increase both the amount and generality of data available for analysis. Thirdly, it is important to extend and complement the current ST-oriented approach. The paper concludes by suggesting some options for triangulating data gathered through a combination of methods.

Contact lens interactions with the tear film

Biochemical changes brought about by the influence of the contact lens on the tear film are conveniently split into two categories. Firstly, the lens can remove or reduce the levels of specific components in the tear film, and secondly, the lens can augment the tear film, by stimulating the influx of new components or increasing the level of existing components. The most obvious tear film components for study in this context are lipids, proteins, mucins and electrolytes. The interactions are affected by the properties of the lens, the characteristics of the individual wearer and the wear schedule. An additional complicating factor is the fact that the lens is many times thicker than the tear film and any immobilised tear components will be more extensively exposed to oxygen and UV radiation than is the case in the absence of a lens. It is arguably the lipoidal components that are most markedly affected by lens wear, since their immobilisation on the lens surface markedly increases their susceptibility to autoxidative degradation. The limited information that is available highlights the importance of subject specificity and suggests that lipid oxidation phenomena are potentially important in contributing to the 'end of day' discomfort of symptomatic contact lens patients. It is clear that tear lipids, although regarded as relatively inert for many years, are now seen as a reactive and potentially important family of compounds in the search for understanding of contact lens-induced discomfort. The influence of the lens on tear proteins shows the greatest range of complexity. Deposition and denaturation can stimulate immune response, lower molecular weight proteins can be extensively absorbed into the lens matrix and the lens can stimulate cascade or upregulation processes leading either to the generation of additional proteins and peptides or an increase in concentration of existing components. Added to this is the stimulating influence of the lens on vascular leakage leading to the influx of plasma proteins such as albumin. The evidence from studies of mucin expression in tears is not consistent and conclusive. This is in part because sample sources, lens materials and methods of analysis vary considerably, and in some cases the study population numbers are low. Expression levels show mucin and material specificity but clear patterns of behaviour are elusive. The electrolyte composition of tears is significantly different from that of other body fluids. Sodium and potassium dominate but potassium ion concentrations in tears are much higher than in serum levels. Calcium and magnesium concentrations in tears are lower than in serum but closer to interstitial fluids. The contact lens provides the potential for increased osmolarity through enhanced evaporation and differential electrolyte concentrations between the anterior and posterior tear films. Since the changes in ocular biochemistry consequent upon contact lens wear are known to be subject-dependent - as indeed is wearer response to the lens - pre-characterisation of individual participant tear chemistry in clinical studies would enhance understanding of these complex effects. © 2013 Elsevier Ltd.

The relation between physical properties of the anterior eye and ocular surface temperature

PURPOSE. To examine the relation between ocular surface temperature (OST) assessed by dynamic thermal imaging and physical parameters of the anterior eye in normal subjects. METHODS. Dynamic ocular thermography (ThermoTracer 7102MX) was used to record body temperature and continuous ocular surface temperature for 8 s after a blink in the right eyes of 25 subjects. Corneal thickness, corneal curvature, and anterior chamber depth (ACD) were assessed using Orbscan II; noninvasive tear break-up time (NIBUT) was assessed using the tearscope; slit lamp photography was used to record tear meniscus height (TMH) and objective bulbar redness. RESULTS. Initial OST after a blink was significantly correlated only with body temperature (r = 0.80, p < 0.0005), NIBUT (r = -0.68, p < 0.005) and corneal curvature (r = -0.40, p = 0.05). A regression model containing all the variables accounted for 70% (p = 0.002) of the variance in OST, of which NIBUT (29%, p = 0.004), and body temperature (18%, p = 0.005) contributed significantly. CONCLUSIONS. The results support previous theoretical models that OST radiation is principally related to the tear film; and demonstrate that it is less related to other characteristics such as corneal thickness, corneal curvature, and anterior chamber depth. © 2007 American Academy of Optometry.

Corrosion of silicon carbide ceramics using conventional and electrochemical methods

Silicon carbide ceramics are candidate materials for use in aggressive environments, including those where aqueous acids are present. Standard corrosion testing methods such as immersion testing are not always sufficiently sensitive for these ceramics owing to the very low, almost unobservable, corrosion rates encountered. Using electrochemical methods the corrosion processes can be assisted, leading to higher rates and thus the elucidation of reaction mechanisms. The behaviour of a sintered and a reaction bonded silicon carbide has been investigated in aqueous HCl, HF, HNO3, and H2SO4, using standard immersion and new electrochemical methods. Both materials were passive in HCl, HNO3, and H2SO4 because of the formation of a surface silica film, and were active in HF. In HF, corrosion of sintered silicon carbide was slight and the residual silicon was removed from reaction bonded specimens.

Immunoblotting and tear sampling techniques for the study of contact lens-induced variations in tear protein profiles

More information on the biochemical interactions taking place between the tear film and the contact lens is required to further our understanding of the causative mechanisms behind the symptoms of dryness and grittiness often experienced by contact lens wearers. These symptoms can often lead to an intolerance to contact lens wear.

Optical quality for keratoconic eyes with conventional RGP lens and simulated, customised contact lens corrections:a comparison

Purpose: To compare monochromatic aberrations of keratoconic eyes when uncorrected, corrected with spherically-powered RGP (rigid gas-permeable) contact lenses and corrected using simulations of customised soft contact lenses for different magnitudes of rotation (up to 15°) and translation (up to 1mm) from their ideal position. Methods: The ocular aberrations of examples of mild, moderate and severe keratoconic eyes were measured when uncorrected and when wearing their habitual RGP lenses. Residual aberrations and point-spread functions of each eye were simulated using an ideal, customised soft contact lens (designed to neutralise higher-order aberrations, HOA) were calculated as a function of the angle of rotation of the lens from its ideal orientation, and its horizontal and vertical translation. Results: In agreement with the results of other authors, the RGP lenses markedly reduced both lower-order aberrations and HOA for all three patients. When compared with the RGP lens corrections, the customised lens simulations only provided optical improvements if their movements were constrained within limits which appear to be difficult to achieve with current technologies. Conclusions: At the present time, customised contact lens corrections appear likely to offer, at best, only minor optical improvements over RGP lenses for patients with keratoconus. If made in soft materials, however, these lenses may be preferred by patients in term of comfort. © 2012 The College of Optometrists.

Transformation through translation:translation policies at Amnesty International

International non-governmental organisations (NGOs) are powerful political players who aim to influence global society. In order to be effective on a global scale, they must communicate their goals and achievements in different languages. Translation and translation policy play an essential role here. Despite NGOs’ important position in politics and society, not much is known about how these organisations, who often have limited funds available, organise their translation work. This study aims to contribute to Translation Studies, and more specifically to investigating institutional translation, by exploring translation policies at Amnesty International, one of the most successful and powerful human rights NGOs around the world. Translation policy is understood as comprising three components: translation management, translation practices, and translation beliefs, based on Spolsky’s study of language policy (2004). The thesis investigates how translation is organised and what kind of policies different Amnesty offices have in place, and how this is reflected in their translation products. The thesis thus also pursues how translation and translation policy impact on the organisation’s message and voice as it is spread around the world. An ethnographic approach is used for the analysis of various data sets that were collected during fieldwork. These include policy documents, guidelines on writing and translation, recorded interviews, e-mail correspondence, and fieldnotes. The thesis at first explores Amnesty’s global translation policy, and then presents the results of a comparative analysis of local translation policies at two concrete institutions: Amnesty International Language Resource Centre in Paris (AILRC-FR) and Amnesty International Vlaanderen (AIVL). A corpus of English source texts and Dutch (AIVL) and French (AILRC-FR) target texts are analysed. The findings of the analysis of translation policies and of the translation products are then combined to illustrate how translation impacts on Amnesty’s message and voice. The research results show that there are large differences in how translation is organised depending on the local office and the language(s), and that this also influences the way in which Amnesty’s message and voice are represented. For Dutch and French specifically, translation policies and translation products differ considerably. The thesis describes how these differences are often the result of different beliefs and assumptions relating to translation, and that staff members within Amnesty are not aware of the different conceptions of translation that exist within Amnesty International as a formal institution. Organising opportunities where translation can be discussed (meetings, workshops, online platforms) can help in reducing such differences. The thesis concludes by suggesting that an increased awareness of these issues will enable Amnesty to make more effective use of translation in its fight against human rights violations.

Translation, transcription, interpreting?

In this talk I discuss some of the problems involved in the transcription and translation of poor quality and/or covertly made recordings. My focus is on how Speech Act Theory can help inform transcription practice. I argue that transcribers should have a good understanding of the pragmatic level of language communication; I illustrate with real case examples how the lack of this understanding can lead to flawed interpretations (and thus potentially miscarriages of justice). I also discuss the problems inherent in forensic translation, where, given the evidential status of the material being translated, the translator’s linguistic choices are often circumscribed by elements of the legal context s/he may not be familiar with.

Knowledge acquisition and research evidence in autism:researcher and practitioner perspectives and engagement

Background: Government policy and national practice guidelines have created an increasing need for autism services to adopt an evidence-based practice approach. However, a gap continues to exist between research evidence and its application. This study investigated the difference between autism researchers and practitioners in their methods of acquiring knowledge. Methods: In a questionnaire study, 261 practitioners and 422 researchers reported on the methods they use and perceive to be beneficial for increasing research access and knowledge. They also reported on their level of engagement with members of the other professional community. Results: Researchers and practitioners reported different methods used to access information. Each group, however, had similar overall priorities regarding access to research information. While researchers endorsed the use of academic journals significantly more often than practitioners, both groups included academic journals in their top three choices. The groups differed in the levels of engagement they reported; researchers indicated they were more engaged with practitioners than vice versa. Conclusions: Comparison of researcher and practitioner preferences led to several recommendations to improve knowledge sharing and translation, including enhancing access to original research publications, facilitating informal networking opportunities and the development of proposals for the inclusion of practitioners throughout the research process.

Wound healing studies and interfacial phenomena:use and relevance of the corneal model

The interaction of the wound dressing as a biomaterial with the wound bed is the central issue of this chapter. The interfacial phenomenon that encompasses the biological and biochemical consequences that arise when a biomaterial is introduced to a host biological environment is discussed. A great deal can be learned from observations arising from the behaviour of biomaterials at other body sites; one particularly relevant body site in the context of wound healing is the anterior eye. The cornea, tear film and posterior surface of the contact lens provide an informative model of the parallel interface that exists between the chronic wound bed, wound fluid and the dressing biomaterial. © 2011 Woodhead Publishing Limited All rights reserved.

The ageing ocular surface:challenges for biomaterials design and function

Changing demographics and in particular an increasingly ageing population, in combination with improved longevity, will have a major impact on changing the face of human diseases and likewise the demand for appropriate biomaterials. The ocular surface is a multifaceted system that combines to create a unique mucosal surface, which includes the cornea, conjunctiva, sclera and lids of the eye. Physical parameters such as the eyelids and eyelashes, combined with the numerous secretory glands that produce the complex tear film, act together to protect and maintain the cornea. Unfortunately an ageing tear film and lacrimal functional unit can lead to impairment of this magnificently orchestrated structure. No single mechanism or modification is responsible but, whatever the cause, the consequence is a reduction in tear stability. An uncompromised tear film is fundamental to a healthy ocular surface. In the face of progressively changing demographics and consequent requirements for medical intervention and medical device developments, it is important to understand what effects the ageing process has on these anterior ocular structures.