Axial length changes with shifts of gaze direction in myopes and emmetropes

Purpose. The purpose of the study was to investigate the changes in axial length occurring with shifts in gaze direction. Methods. Axial length measurements were obtained from the left eye of 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 noncontact optical biometer in each of the nine different cardinal directions of gaze over 5 minutes. The subject's fellow eye fixated on an external distance (6 m) target to control accommodation, also with 15° deviation. Axial length measurements were also performed in 15° and 25° downward gaze with the biometer inclined on a tilting table, allowing gaze shifts to be achieved with either full head turn but no eye turn, or full eye turn with no head turn. Results. 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 inferonasal gaze (P < 0.001) and a slight decrease in axial length in superior gaze (−12 ± 17 μm) compared with primary gaze (P < 0.001). In downward gaze, a significant axial elongation occurred when eye turn was used (P < 0.001), but not when head turn was used to shift gaze (P > 0.05). Conclusions. The angle of gaze has a small but significant short-term effect on axial length, with greatest elongation occurring in inferonasal gaze. The elongation of the eye appears to be due to the influence of the extraocular muscles, in particular the oblique muscles.

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.

Homing abilities of the tropical primitively eusocial paper wasp Ropalidia marginata

Compared to our extensive knowledge about the navigation and homing abilities of ants and bees, we know rather little about these phenomena in social wasps. Here, we report the homing abilities of the tropical primitively eusocial wasp Ropalidia marginata and the factors that affect their homing success. To determine from how far these wasps can return to their nests, we transported foragers blindfold and released them at gradually increasing distances from their nests in four cardinal directions. Their homing success was determined by checking their presence on their nests on three consecutive nights. All foragers (56 individuals, 115 releases) returned back from an area of 0.73 +/- A 0.25 km(2) on the day of release (minimal homing area), whereas 83.8 % of the foragers (217 individuals, 420 releases) returned when we enlarged the area of release to 6.22 +/- A 0.66 km(2) around their nests (maximal homing area). Of 66 releases, no wasps returned from beyond the maximal homing area. The minimal homing area might be familiar to the foragers because they probably routinely forage in this area and the maximal homing area represents the maximum distances from which the wasps are capable of returning to their nests, with or without familiarity.

Dispersão de machos de Diatraea saccharalis (Fabricius) (Leipdoptera: Crambidae) em cana-de-açúcar

Pós-graduação em Agronomia (Entomologia Agrícola) - FCAV

Étude de l’orientation cardinale sud dans les sépultures mayas de la Période Classique

Ce mémoire porte sur l’étude de l’orientation des sépultures mayas de la Période Classique (250 - 900/1000 de notre ère). Il s’agit d’une recherche visant à comprendre le choix d’une orientation sud des défunts dans la vallée du Belize et ses environs. L’intérêt porté à cette région vient du fait que l’orientation sud des défunts est un phénomène que l’on retrouve rarement sur le territoire maya, sauf à cet endroit. Alors que la présence de la cardinalité en lien avec la cosmovision maya est attestée dans l’architecture, le plan des sites, la forme et la fonction des divinités, dans l’agriculture, etc., il est plutôt rare qu’elle soit analysée dans les études du traitement funéraire. Ainsi, le but de cette recherche est de saisir l’ampleur de la pratique de l’orientation sud des défunts sur le territoire maya, de comprendre son origine et sa ou ses possible(s) signification(s). Les données des sépultures de la Période Classique de cinq sites de la vallée du Belize (Baking Pot, Barton Ramie, Blackman Eddy, Cahal Pech et Xunantunich), de quatre sites du Plateau Vaca (Minanha, Pacbitun, Mountain Cow et Caracol) et de trois sites situés à l’ouest (Holmul) et au nord (San José et Altun Ha) de ces deux régions sont compilées. Les résultats révèlent que le coeur de cette pratique se trouve dans la vallée du Belize, bien qu’une orientation sud des défunts ait été retrouvée partout. Cette pratique semble apparaitre à la fin de la Période Préclassique et les analyses ne révèlent pas de lien entre l’orientation sud et certaines variables (âge, sexe, position du défunt). Finalement, on arrive à la conclusion qu’il est possible que cette orientation sud des défunts soit en lien avec le passage des défunts dans l’inframonde et que cela forme un choix culturel local en lien avec le statut et l’identité du défunt.

Étude de l’orientation cardinale sud dans les sépultures mayas de la Période Classique

Ce mémoire porte sur l’étude de l’orientation des sépultures mayas de la Période Classique (250 - 900/1000 de notre ère). Il s’agit d’une recherche visant à comprendre le choix d’une orientation sud des défunts dans la vallée du Belize et ses environs. L’intérêt porté à cette région vient du fait que l’orientation sud des défunts est un phénomène que l’on retrouve rarement sur le territoire maya, sauf à cet endroit. Alors que la présence de la cardinalité en lien avec la cosmovision maya est attestée dans l’architecture, le plan des sites, la forme et la fonction des divinités, dans l’agriculture, etc., il est plutôt rare qu’elle soit analysée dans les études du traitement funéraire. Ainsi, le but de cette recherche est de saisir l’ampleur de la pratique de l’orientation sud des défunts sur le territoire maya, de comprendre son origine et sa ou ses possible(s) signification(s). Les données des sépultures de la Période Classique de cinq sites de la vallée du Belize (Baking Pot, Barton Ramie, Blackman Eddy, Cahal Pech et Xunantunich), de quatre sites du Plateau Vaca (Minanha, Pacbitun, Mountain Cow et Caracol) et de trois sites situés à l’ouest (Holmul) et au nord (San José et Altun Ha) de ces deux régions sont compilées. Les résultats révèlent que le coeur de cette pratique se trouve dans la vallée du Belize, bien qu’une orientation sud des défunts ait été retrouvée partout. Cette pratique semble apparaitre à la fin de la Période Préclassique et les analyses ne révèlent pas de lien entre l’orientation sud et certaines variables (âge, sexe, position du défunt). Finalement, on arrive à la conclusion qu’il est possible que cette orientation sud des défunts soit en lien avec le passage des défunts dans l’inframonde et que cela forme un choix culturel local en lien avec le statut et l’identité du défunt.

Religious emblems : being a series of emblematic engravings, with written explanations, miscellaneous observations and religious reflections, designed to illustrate divine truth, in accordance with the cardinal principles of Christianity /

With this are bound: Holmes, w. REligious allegories. 1860; and Baxter, R. Directions for getting ... spiritual peace. [18--?]

Middle years teacher education : new programs and research directions

Teacher education programs focussing on the development of specialist teachers for 'the middle years' have proliferated in Australian universities in recent years. This paper provides some insights into middle years' teacher education programs at the University of Queensland, Edith Cowan and Flinders Universities with regard to their: philosophical underpinnings; specific educational context; scope and nature of the program. In addition, some of the research directions and efficacy strategies utilised in conjunction with the programs will be shared, along with some early findings from a longitudinal study in one of the programs. We propose that the pattern of programmatic growth heralds a new time for teacher education, and we speculate about the production of new kinds of teacher identities as graduates take their place in the profession.

Sustainable transport and the impact on the built environment : Future trends and directions

We love the automobile and the independence that it gives us. We are more mobile than we have ever been before in recorded history. In Australia 80% of journeys are by private motor vehicle. But it is becoming increasingly obvious that this era has a very limited lifespan. Fuel prices have skyrocketed recently with no end in sight. In spite of massive amounts of road construction, our cities are becoming increasingly congested. We desperately need to address climate change and the automobile is a major contributor. Carbon trading schemes will put even more upward pressure on fuel prices. At some point in the near future, most of us will need to reconsider our automobile usage whether we like it or not. The time to plan for the future is now. But what will happen to our mobility when access to cheap and available petroleum becomes a thing of the past? Will we start driving electric/hydrogen/ethanol vehicles? Or will we flock to public transport? Will our public transport systems cope with a massive increase in demand? Will thousands of people take to alternatives such as bicycles? If so, where do we put them? How do we change our roads to cope? How do we change our buildings to suit? Will we need recharging stations in our car park for example? Some countries are less reliant on the car than others e.g. Holland and Germany. How can the rest of the world learn from them? This paper discusses many of the likely outcomes of the inevitable shift away from society’s reliance on petroleum and examines the expected impact on the built environment. It also looks at ways in which the built environment can be planned to help ease the transition to a fossil free world. 1.

Off-site Manufacture in Australia : Current State and Future Directions

Off-site manufacture (OSM) offers numerous benefits to all parties in the construction process. The uptake of OSM in Australia has, however, been limited. This limited uptake corresponds to similar trends in the UK and US, although the level of OSM there appears to be increasing. This project undertook three workshops — one each in Victoria, Queensland and Western Australia — and 18 interviews with key stakeholders to assist in identifying the general benefits and barriers to OSM uptake in the Australian construction industry. Seven case studies were also undertaken, involving construction projects that used OSM, ranging from civil projects through to residential. Each of these case studies has been analysed to identify what worked and what didn’t, and suggest the lessons to be learned from each project.

PEPA workshops for allied health professionals : outcomes and directions for the future

The Program of Experience in the Palliative Approach (PEPA) started in 2003 as an initiative of the Australian Government, Department of Health and Ageing. The overall aim of PEPA is to improve the quality, availability and access to palliative care for people who are dying, and their families, by providing high quality learning experiences for primary care providers, including allied health professionals. As part of the program, an allied health workshop program has been developed following an extensive review of the literature and in consultation with experts in the field. The PEPA allied health workshops are offered across all states/territories.

Future directions and perspectives for problem solving research and curriculum development

Since the 1960s, numerous studies on problem solving have revealed the complexity of the domain and the difficulty in translating research findings into practice. The literature suggests that the impact of problem solving research on the mathematics curriculum has been limited. Furthermore, our accumulation of knowledge on the teaching of problem solving is lagging. In this first discussion paper we initially present a sketch of 50 years of research on mathematical problem solving. We then consider some factors that have held back problem solving research over the past decades and offer some directions for how we might advance the field. We stress the urgent need to take into account the nature of problem solving in various arenas of today’s world and to accordingly modernize our perspectives on the teaching and learning of problem solving and of mathematical content through problem solving. Substantive theory development is also long overdue—we show how new perspectives on the development of problem solving expertise can contribute to theory development in guiding the design of worthwhile learning activities. In particular, we explore a models and modeling perspective as an alternative to existing views on problem solving.