Optical and biomechanical factors, associated with near work and myopia

Near work may play an important role in the development of myopia in the younger population. The prevalence of myopia has also been found to be higher in occupations that involve substantial near work tasks, for example in microscopists and textile workers. When nearwork is performed, it typically involves accommodation, convergence and downward gaze. A number of previous studies have examined the effects of accommodation and convergence on changes in the optics and biometrics of the eye in primary gaze. However, little is known about the influence of accommodation on the eye in downward gaze. This thesis is primarily concerned with investigating the changes in the eye during near work in downward gaze under natural viewing conditions. To measure wavefront aberrations in downward gaze under natural viewing conditions, we modified a commercial Shack-Hartmann wavefront sensor by adding a relay lens system to allow on-axis ocular aberration measurements in primary gaze and downward gaze, with binocular fixation. Measurements with the modified wavefront sensor in primary and downward gaze were validated against a conventional aberrometer using both a model eye and in 9 human subjects. We then conducted an experiment to investigate changes in ocular aberrations associated with accommodation in downward gaze over 10 mins in groups of both myopes (n = 14) and emmetropes (n =12) using the modified Shack-Hartmann wavefront sensor. During the distance accommodation task, small but significant changes in refractive power (myopic shift) and higher order aberrations were observed in downward gaze compared to primary gaze. Accommodation caused greater changes in higher order aberrations (in particular coma and spherical aberration) in downward gaze than primary gaze, and there was evidence that the changes in certain aberrations with accommodation over time were different in downward gaze compared to primary gaze. There were no obvious systematic differences in higher order aberrations between refractive error groups during accommodation or downward gaze for fixed pupils. However, myopes exhibited a significantly greater change in higher order aberrations (in particular spherical aberration) than emmetropes for natural pupils after 10 mins of a near task (5 D accommodation) in downward gaze. These findings indicated that ocular aberrations change from primary to downward gaze, particularly with accommodation. To understand the mechanism underlying these changes in greater detail, we then extended this work to examine the characteristics of the corneal optics, internal optics, anterior biometrics and axial length of the eye during a near task, in downward gaze, over 10 mins. Twenty young adult subjects (10 emmetropes and 10 myopes) participated in this study. To measure corneal topography and ocular biometrics in downward gaze, a rotating Scheimpflug camera and an optical biometer were inclined on a custom built, height and tilt adjustable table. We found that both corneal optics and internal optics change with downward gaze, resulting in a myopic shift (~0.10 D) in the spherical power of the eye. The changes in corneal optics appear to be due to eyelid pressure on the anterior surface of the cornea, whereas the changes in the internal optics (an increase in axial length and a decrease in anterior chamber depth) may be associated with movement of the crystalline lens, under the action of gravity, and the influence of altered biomechanical forces from the extraocular muscles on the globe with downward gaze. Changes in axial length with accommodation were significantly greater in downward gaze than primary gaze (p < 0.05), indicating an increased effect of the mechanical forces from the ciliary muscle and extraocular muscles. A subsequent study was conducted to investigate the changes in anterior biometrics, axial length and choroidal thickness in nine cardinal gaze directions under the actions of the extraocular muscles. Ocular biometry measurements were obtained from 30 young adults (10 emmetropes, 10 low myopes and 10 moderate myopes) through a rotating prism with 15° deviation, along the foveal axis, using a non-contact optical biometer in each of nine different cardinal directions of gaze, over 5 mins. There was a significant influence of gaze angle and time on axial length (both p < 0.001), with the greatest axial elongation (+18 ± 8 μm) occurring with infero-nasal gaze (p < 0.001) and a slight decrease in axial length in superior gaze (−12 ± 17 μm) compared with primary gaze (p < 0.001). There was a significant correlation between refractive error (spherical equivalent refraction) and the mean change in axial length in the infero-nasal gaze direction (Pearson's R2 = 0.71, p < 0.001). To further investigate the relative effect of gravity and extraocular muscle force on the axial length, we measured axial length in 15° and 25° downward gaze with the biometer inclined on a tilting table that allowed gaze shifts to occur with either full head turn but no eye turn (reflects the effect of gravity), or full eye turn with no head turn (reflects the effect of extraocular muscle forces). We observed a significant axial elongation in 15° and 25° downward gaze in the full eye turn condition. However, axial length did not change significantly in downward gaze over 5 mins (p > 0.05) in the full head turn condition. The elongation of the axial length in downward gaze appears to be due to the influence of the extraocular muscles, since the effect was not present when head turn was used instead of eye turn. The findings of these experiments collectively show the dynamic characteristics of the optics and biometrics of the eye in downward gaze during a near task, over time. These were small but significant differences between myopic and emmetropic eyes in both the optical and biomechanical changes associated with shifts of gaze direction. These differences between myopes and emmetropes could arise as a consequence of excessive eye growth associated with myopia. However the potentially additive effects of repeated or long lasting near work activities employing infero-nasal gaze could also act to promote elongation of the eye due to optical and/or biomechanical stimuli.

Effects of joint thickness, adhesion and web shells to the face shell bedded concrete masonry loaded in compression

The Australian masonry standard allows either prism tests or correction factors based on the block height and mortar thickness to evaluate masonry compressive strength. The correction factor helps the taller units with conventional 10 mm mortar being not disadvantaged due to size effect. In recent times, 2-4 mm thick, high-adhesive mortars and H blocks with only the mid-web shell are used in masonry construction. H blocks and thinner and higher adhesive mortars have renewed interest of the compression behaviour of hollow concrete masonry and hence is revisited in this paper. This paper presents an experimental study carried out to examine the effects of the thickness of mortar joints, the type of mortar adhesives and the presence of web shells in the hollow concrete masonry prisms under axial compression. A non-contact digital image correlation technique was used to measure the deformation of the prisms and was found adequate for the determination of strain fi eld of the loaded face shells subjected to axial compression. It is found that the absence of end web shells lowers the compressive strength and stiffness of the prisms and the thinner and higher adhesive mortars increase the compressive strength and stiffness, while lowering the Poisson's ratio. © Institution of Engineers Australia, 2013.

Bistable regime of surface magnetoplasma waves excitation at a semiconductor-metal interface

The theoretical analysis of the bistability associated with the excitation of surface magnetoplasma waves (SWs) propagating across an external magnetic field at the semiconductor-metal interface by the attenuated total reflection (ATR) method is presented. The Kretschmann-Raether configuration of the ATR method is considered, i.e. a plane electromagnetic wave is incident onto a metal surface through a coupling prism. The third-order nonlinearity of the semiconductor medium is considered in the general form using the formalism of the third-order nonlinear susceptibilities and of the perturbation theory. The examples of the nonlinear mechanisms which influence the SW propagation are given. The analytical and numerical analyses show that the realization of bistable regimes of the SW excitation is possible. The SW amplitude values providing bistability in the structure are evaluated and are reasonably low to provide the experimental observation.

The rise of englightened shareholder primacy and its impact on US corporate self-regulation

Enlightened shareholder primacy (“ESP”) is a new approach in the corporate governance (“CG”) framework. The emergence of this approach is important owing to its role in answering a vital question: is the company really a private organisation to be seen only through the economic prism of contract? Or is it public and about a wider group of interests and underwritten by communitarian concern about social responsibility? Apart from answering this question, ESP explains the changes in corporate directors’ roles and self-regulation strategies of companies.

Primary and substance-induced psychotic disorders in methamphetamine users

This study investigates the rates of primary psychotic disorders (PPD) and substance induced psychotic disorders (SIPDs) in methamphetamine (MA) users accessing needle and syringe programs (NSPs). The aim was to determine if there are systematic differences in the characteristics of MA users with PPDs and SIPDs compared to those with no psychotic disorder. Participants were 198 MA users reporting use in the previous month. Diagnosis was determined using the Psychiatric Research Interview for DSM-IV Substance and Mental Disorders (PRISM-IV). Current psychiatric symptoms and substance use were also measured. Just over half (N=101) of participants met DSM-IV criteria for a lifetime psychotic disorder, including 81 (80%) with a SIPD and 20 (20%) with a PPD. Those with a younger age of onset of weekly MA use were at increased risk of a lifetime SIPD. A current psychotic disorder was found in 62 (39%), comprising 49 SIPDs (79%) and 13 PPDs (21%). MA users with a current PPD were more likely to have received psychiatric treatment in the past month than those with a current SIPD, despite a similar level of psychotic symptom severity. A high proportion of MA users accessing NSPs have psychotic disorders, the majority of which are substance-induced.

Effect of bifocal and prismatic bifocal spectacles on myopia progression in children

Importance Myopia is a significant public health problem, making it important to determine whether a bifocal spectacle treatment involving near prism slows myopia progression in children. Objective To determine whether bifocal and prismatic bifocal spectacles control myopia in children with high rates of myopia progression and to assess whether the treatment effect is dependent on the lag of accommodation and/or near phoria status. Design, Setting, and Participants This 3-year randomized clinical trial was conducted in a private practice. A total of 135 (73 female and 62 male) Chinese-Canadian children (aged 8-13 years; mean [SE] age, 10.29 [0.15] years; mean [SE] myopia, −3.08 [0.10] D) with myopia progression of at least 0.50 D in the preceding year were randomly assigned to 1 of 3 treatments. A total of 128 (94.8%) completed the trial. Interventions Single-vision lenses (control, n = 41), +1.50-D executive bifocals (n = 48), and +1.50-D executive bifocals with 3-Δ base-in prism in the near segment of each lens (n = 46). Main Outcomes and Measures Myopia progression (primary) measured using an automated refractor following cycloplegia and increase in axial length (secondary) measured using ultrasonography at intervals of 6 months for 36 months. Results Myopia progression over 3 years was an average (SE) of −2.06 (0.13) D for the single-vision lens group, −1.25 (0.10) D for the bifocal group, and −1.01 (0.13) D for the prismatic bifocal group. Axial length increased an average (SE) of 0.82 (0.05) mm, 0.57 (0.07) mm, and 0.54 (0.06) mm, respectively. The treatment effect of bifocals (0.81 D) and prismatic bifocals (1.05 D) was significant (P < .001). Both bifocal groups had less axial elongation (0.25 mm and 0.28 mm, respectively) than the single-vision lens group (P < .001). For children with high lags of accommodation (≥1.01 D), the treatment effect of both bifocals and prismatic bifocals was similar (1.1 D) (P < .001). For children with low lags (<1.01 D), the treatment effect of prismatic bifocals (0.99 D) was greater than of bifocals (0.50 D) (P = .03). The treatment effect of both bifocals and prismatic bifocals was independent of the near phoria status. Conclusions and Relevance Bifocal spectacles can slow myopia progression in children with an annual progression rate of at least 0.50 D after 3 years. These results suggest that prismatic bifocals are more effective for myopic children with low lags of accommodation.

Sustainability in infrastructure investment : building the business case

Many infrastructure agencies adopt sustainability objectives at a corporate level and incorporate sustainability targets and indicators as part of corporate reporting processes. These objectives are expected to translate to all stages of the project delivery process, including project selection. For infrastructure capital works projects and programs, a robust project management approach involves the development of a business case to guide investment decision making. A key tool in the assessment of project options and selection of a delivery strategy is Cost Benefit Analysis (CBA). Infrastructure providers are required to undertake cost benefit analysis to support project selection through regulatory approval and budgetary processes. This tool has emerged through the prism of economic analysis rather than sustainability. A literature review reveals the limitations of CBA alone to effectively evaluate economic, environmental and social externalities or impacts that apply over a long time frame, and that are ultimately irreversible. Multi-Criteria Analysis (MCA) has been introduced as a means to incorporate a wider array of factors into decision making such as sustainability. This, however, presents new challenges with issues around how to transparently represent wider community values in the selection of a preferred solution. Are these tools effective in assessing the wider sustainability costs and benefits taking into account that these are public works with long life spans and significant impacts across institutional boundaries? The research indicates a need to develop clear guidelines for investment decision making in order to better align with corporate sustainability objectives. Findings from the literature review indicate that a more sustainable approach to investment decision-making framework should include: the incorporation of sustainability goals from corporate planning documents; problem definition and option generation using best practice investment management guidelines; improved guidelines for Business Case development using a combination of both Cost Benefit Analysis and Multi-Criteria Analysis; and an integrated public participation process.

A finite element modelling method for thin layer mortared masonry systems

This paper deals with a finite element modelling method for thin layer mortared masonry systems. In this method, the mortar layers including the interfaces are represented using a zero thickness interface element and the masonry units are modelled using an elasto-plastic, damaging solid element. The interface element is formulated using two regimes; i) shear-tension and ii) shearcompression. In the shear-tension regime, the failure of joint is consiedered through an eliptical failure criteria and in shear-compression it is considered through Mohr Coulomb type failure criterion. An explicit integration scheme is used in an implicit finite element framework for the formulation of the interface element. The model is calibrated with an experimental dataset from thin layer mortared masonry prism subjected to uniaxial compression, a triplet subjected to shear loads a beam subjected to flexural loads and used to predict the response of thin layer mortared masonry wallettes under orthotropic loading. The model is found to simulate the behaviour of a thin layer mortated masonry shear wall tested under pre-compression and inplane shear quite adequately. The model is shown to reproduce the failure of masonry panels under uniform biaxial state of stresses.

Positive development and assessment

Purpose – There has been a tendency in sustainability science to be passive. The purpose of this paper is to introduce an alternative positive framework for a more active and direct approach to sustainable design and assessment that de-couples environmental impacts and economic growth. Design/methodology/approach – This paper deconstructs some systemic gaps that are critical to sustainability in built environment management processes and tools, and reframes negative “sustainable” decision making and assessment frameworks into their positive counterparts. In particular, it addresses the omission of ecology, design and ethics in development assessment. Findings – Development can be designed to provide ecological gains and surplus “eco-services,” but assessment tools and processes favor business-as-usual. Despite the tenacity of the dominant paradigm (DP) in sustainable development institutionalized by the Brundtland Report over 25 years ago, these omissions are easily corrected. Research limitations/implications – The limitation is that the author was unable to find exceptions to the omissions cited here in the extensive literature on urban planning and building assessment tools. However, exceptions prove the rule. The implication is that it is not too late for eco-positive retrofitting of cities to increase natural and social capital. The solutions are just as applicable in places like China and India as the USA, as they pay for themselves. Originality/value – Positive development (PD) is a fundamental paradigm shift that reverses the negative models, methods and metrics of the DP of sustainable development. This paper provides an example of how existing “negative” concepts and practices can be converted into positive ones through a PD prism. Through a new form of bio-physical design, development can be a sustainability solution.

Narrative as a tool for critical reflective practice in the creative industries

This paper explores the efficacy of narrative in reflective practice across a range of creative disciplines. As practitioners within the creative industries the authors internalise experience and re-contextualise it as stories, designs, music videos, fiction and non-fiction films and dance. They are uniquely placed to examine narrative in critical reflection through the prism of their creative practice and in so doing offer insights into reconceptualising professional practice. The authors demonstrate how engagement with and reflection on and in their stories enables wider reflection. Their purpose in reflection is not just to learn from mistakes but to develop an epistemology of practice that enables them to apply rigorous academic inquiry to articulate their tacit professional knowledge and establish new methods for dealing with uncertainty in creative practice research.

A novel human leucocyte antigen-DRB1 genotyping method based on multiplex primer extension reactions

We have developed and validated a semi-automated fluorescent method of genotyping human leucocyte antigen (HLA)-DRB1 alleles, HLA-DRB1*01-16, by multiplex primer extension reactions. This method is based on the extension of a primer that anneals immediately adjacent to the single-nucleotide polymorphism with fluorescent dideoxynucleotide triphosphates (minisequencing), followed by analysis on an ABI Prism 3700 capillary electrophoresis instrument. The validity of the method was confirmed by genotyping 261 individuals using both this method and polymerase chain reaction with sequence-specific primer (PCR-SSP) or sequencing and by demonstrating Mendelian inheritance of HLA-DRB1 alleles in families. Our method provides a rapid means of performing high-throughput HLA-DRB1 genotyping using only two PCR reactions followed by four multiplex primer extension reactions and PCR-SSP for some allele groups. In this article, we describe the method and discuss its advantages and limitations.

Stability of Dimeric Interface in Banana Lectin: Insight from Molecular Dynamics Simulations

Banana lectin (Banlec) is a homodimeric non-glycosylated protein. It exhibits the b-prism I structure. High-temperature molecular dynamics simulations have been utilized to monitor and understand early stages of thermally induced unfolding of Banlec. The present study elucidates the behavior of the dimeric protein at four different temperatures and compares the structural and conformational changes to that of the minimized crystal structure. The process of unfolding was monitored by following the radius of gyration, the rms deviation of each residue, change in relative solvent accessibility and the pattern of inter- and intra-subunit interactions. The overall study demonstrates that the Banlec dimer is a highly stable structure, and the stability is mostly contributed by interfacial interactions. It maintains its overall conformation during high-temperature (400–500 K) simulations, with only the unstructured loop regions acquiring greater momentum under such condition. Nevertheless, at still higher temperatures (600 K) the tertiary structure is gradually lost which later extends to loss of secondary structural elements. The pattern of hydrogen bonding within the subunit and at the interface across different stages has been analyzed and has provided rationale for its intrinsic high stability.

Pour une éthique du traducteur poéticien

This doctoral thesis starts with a comprehensive introduction seeking to anchor the problematics of the ethics of the poetician translator (a translator of literary and similar texts) in a theoretical framework drawing on moral philosophy. This introductory section is followed by six published papers (four journal articles and two papers from conference proceedings), forming the main body of the thesis, which progressively develop a possible application of this theoretical framework. Starting from the acknowledgement that one of the ethical stakes in translation is constructed around the relation to the foreign and to the other , the translation process is scrutinized through the prism of the philosophies of Dialogue , focusing on how the translating actors relate to their task. The central notions around which philosophies of Dialogue are built are introduced and applied to translation. The question of intersubjective relations, addressed from a philosophical perspective, is developed with the help of the works of Martin Buber, Gabriel Marcel, Emmanuel Levinas and Paul Ric ur. The introductory section presents and explicates the thought of each of these philosophers and extracts the concepts that are then developed in the articles and conference papers collected here. Each paper concentrates on the notions of one of the philosophers referred to above and places these notions in perspective with other philosophies of Dialogue. All the papers contribute to explicating the relationship between the multiple philosophical notions that address the problematics of alterity and the condition of the translator. The work as a whole leads to the idea that the task of the poetician translator is not only to translate a text properly but above all to rouse and increase the desire of linguistic communities to live together.

Size-dependent melting of nanoparticles: Hundred years of thermodynamic model

Thermodynamic model first published in 1909, is being used extensively to understand the size-dependent melting of nanoparticles. Pawlow deduced an expression for the size-dependent melting temperature of small particles based on the thermodynamic model which was then modified and applied to different nanostructures such as nanowires, prism-shaped nanoparticles, etc. The model has also been modified to understand the melting of supported nanoparticles and superheating of embedded nanoparticles. In this article, we have reviewed the melting behaviour of nanostructures reported in the literature since 1909.

Fictionalising Trauma : The Aesthetics of Marguerite Duras's India Cycle

Marguerite Duras (1914−1996) was one of the most original French writers and film directors, whose cycles are renowned for a transgeneric repetition variation of human suffering in the modern condition. Her fictionalisation of Asian colonialism, the India Cycle (1964−1976), consists of three novels, Le ravissement de Lol V. Stein (1964), Le Vice-consul (1966) and L'amour (1971), a theatre play, India Song (1973), and three films, La Femme du Gange (1973), India Song (1974) and Son nom de Venise dans Calcutta desért (1976). Duras’s cultural position as a colon in inter-war ‘Indochina’ was the backdrop for this “théâtre-text-film”, while its creation was provoked by the atrocities of World War II and post-war decolonisation. Fictionalising Trauma analyses the aesthetics of the India Cycle as Duras’s critical working-through of historical trauma. From an emotion-focused cognitive viewpoint, the study sheds light on trauma’s narrativisation using the renewed concept of traumatic memory developed by current social neuroscience. Duras is shown to integrate embodied memory and narrative memory into an emotionally progressing fiction. Thus the rhetoric of the India Cycle epitomises a creative symbolisation of the unsayable, which revises the concept of trauma from a semiotic failure into an imaginative metaphorical process. The India Cycle portrays the stagnated situation of a white society in Europe and British India during the thirties. The narratives of three European protagonists and one fictional Cambodian mendicant are organised as analogues mirroring the effects of rejection and loss on both sides of the colonial system. Using trauma as a conceptual prism, the study rearticulates this composition as three roles: those of witnessing writers, rejected survivors and colonial perpetrators. Three problems are analysed in turn by reading the non-verbal markers of the text: the white man as a witness, the subversive trope of the madwoman and the deadlock of the colonists’ destructive passion. The study reveals emotion and fantasy to be crucial elements in critical trauma fiction. Two devices intertwine throughout the cycle: affective images of trauma expressing the horror of life and death, and self-reflexive metafiction distancing the face-value of the melodramatic stories. This strategy dismantles racist and sexist discourses underpinning European life, thus demanding a renewal of cultural memory by an empathic listening to the ‘other’. And as solipsism and madness lead the lives of the white protagonists to tragic ends, the ‘real’ beggar in Calcutta lives in ecological harmony with Nature. This emphasises the failure of colonialism, as the Durasian phantasm ambiguously strives for a deconstruction of the exotic mythical fiction of French ‘Indochina’.