967 resultados para computably enumerable degrees


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Railway level crossings present an arguably unique interface between two transport systems that differ markedly in their performance characteristics, their degrees of regulation and their safety cultures. Railway level crossings also differ dramatically in the importance they represent as safety issues for the two modes. For rail, they are the location of a large proportion of fatalities within the system and are therefore the focus of much safety concern. For the road system, they comprise only a few percent of all fatalities, although the potential for catastrophic outcomes exist. Rail operators and regulators have traditionally required technologies to be failsafe and to demonstrate high levels of reliability. The resultant level of complexity and cost has both limited their extent of application and led to a need to better understand how motorists comprehend and respond to these systems.

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PURPOSE: To examine the symmetry of corneal changes following near work in the fellow eyes of non-amblyopic myopic anisometropes. METHODS: Thirty-four non-amblyopic myopic anisometropes (minimum 1 D spherical equivalent anisometropia) were recruited. Corneal topography was measured with the Medmont E300 Videokeratoscope before and after a controlled near task. Subjects were positioned to minimise head movements and read continuous text on a computer monitor for 10 minutes at an angle of 25 degrees downward gaze and an accommodation demand of 2.5 D. Measures of palpebral aperture morphology during primary and downward gaze were also obtained using digital photography and analysed with customised software. RESULTS: Significant changes in corneal topography were observed after ten minutes of reading. Localised superior regions of corneal topographical change (a hyperopic shift in corneal power) were typically exhibited in both eyes following the near task. The mean change in the corneal sphero-cylinder was +0.02/-0.11 x 113 and +0.02/-0.06 x 68 for the more and less myopic eyes respectively for a 6 mm corneal diameter. A significantly greater change in corneal astigmatism power vector J0 (a larger increase in against the rule astigmatism) was observed in the more myopic eyes (p < 0.01 for a 6 mm diameter). The more and less myopic eyes exhibited a high degree of interocular symmetry for measures of palpebral aperture morphology during both primary and downward gaze. Changes in corneal power vectors following reading were associated with eyelid position during downward gaze. CONCLUSIONS: Changes in corneal topography observed following a controlled reading task were highly symmetrical between the fellow eyes of myopic anisometropes due to the interocular symmetry of the palpebral aperture. However, the more myopic eye did exhibit a small but significantly greater magnitude of change in corneal astigmatism compared to the less myopic eye following reading. These findings may have implications for understanding the mechanism of development of non-amblyopic myopic anisometropia.

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BACKGROUND: Melanoma is the most lethal form of skin cancer, but recent advances in molecularly targeted agents against the Ras/Raf/MAPK pathway demonstrate promise as effective therapies. Despite these advances, resistance remains an issue, as illustrated recently by the clinical experience with vemurafenib. Such acquired resistance appears to be the result of parallel pathway activation, such as PI3K, to overcome single-agent inhibition. In this report, we describe the cytotoxicity and anti-tumour activity of the novel MEK inhibitor, E6201, in a broad panel of melanoma cell lines (n = 31) of known mutational profile in vitro and in vivo. We further test the effectiveness of combining E6201 with an inhibitor of PI3K (LY294002) in overcoming resistance in these cell lines. RESULTS: The majority of melanoma cell lines were either sensitive (IC50 < 500 nM, 24/31) or hypersensitive (IC50 < 100 nM, 18/31) to E6201. This sensitivity correlated with wildtype PTEN and mutant BRAF status, whereas mutant RAS and PI3K pathway activation were associated with resistance. Although MEK inhibitors predominantly exert a cytostatic effect, E6201 elicited a potent cytocidal effect on most of the sensitive lines studied, as evidenced by Annexin positivity and cell death ELISA. Conversely, E6201 did not induce cell death in the two resistant melanoma cell lines tested. E6201 inhibited xenograft tumour growth in all four melanoma cell lines studied to varying degrees, but a more pronounced anti-tumour effect was observed for cell lines that previously demonstrated a cytocidal response in vitro. In vitro combination studies of E6201 and LY294002 showed synergism in all six melanoma cell lines tested, as defined by a mean combination index < 1. CONCLUSIONS: Our data demonstrate that E6201 elicits a predominantly cytocidal effect in vitro and in vivo in melanoma cells of diverse mutational background. Resistance to E6201 was associated with disruption of PTEN and activation of downstream PI3K signalling. In keeping with these data we demonstrate that co-inhibition of MAPK and PI3K is effective in overcoming resistance inherent in melanoma.

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Geminiviruses of the genera Begomovirus and Curtovirus utilize three replication modes: complementary-strand replication (CSR), rolling-circle replication (RCR) and recombinationdependent replication (RDR). Using two-dimensional gel electrophoresis, we now show for the first time that maize streak virus (MSV), the type member of the most divergent geminivirus genus, Mastrevirus, does the same. Although mastreviruses have fewer regulatory genes than other geminiviruses and uniquely express their replication-associated protein (Rep) from a spliced transcript, the replicative intermediates of CSR, RCR and RDR could be detected unequivocally within infected maize tissues. All replicative intermediates accumulated early and, to varying degrees, were already present in the shoot apex and leaves at different maturation stages. Relative to other replicative intermediates, those associated with RCR increased in prevalence during leaf maturation. Interestingly, in addition to RCR-associated DNA forms seen in other geminiviruses, MSV also apparently uses dimeric open circular DNA as a template for RCR. © 2010 SGM.

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Glass Pond is an interactive artwork designed to engender exploration and reflection through an intuitive, tangible interface and a simulation agent. It is being developed using iterative methods. A study has been conducted with the aim of illuminating user experience, interface, design, and performance issues.The paper describes the study methodology and process of data analysis including coding schemes for cognitive states and movements. Analysis reveals that exploration and reflection occurred as well as composing behaviours (unexpected). Results also show that participants interacted to varying degrees. Design discussion includes the artwork's (novel) interface and configuration.

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Authigenic illite-smectite and chlorite in reservoir sandstones from several Pacific rim sedimentary basins in Australia and New Zealand have been examined using an Electroscan Environmental Scanning Electron Microscope (ESEM) before, during, and after treatment with fresh water and HCl, respectively. These dynamic experiments are possible in the ESEM because, unlike conventional SEMs that require a high vacuum in the sample chamber (10-6 torr), the ESEM will operate at high pressures up to 20 torr. This means that materials and processes can be examined at high magnifications in their natural states, wet or dry, and over a range of temperatures (-20 to 1000 degrees C) and pressures. Sandstones containing the illite-smectite (60-70% illite interlayers) were flushed with fresh water for periods of up to 12 hours. Close examination of the same illite-smectite lines or filled pores, both before and after freshwater treatments, showed that the morphology of the illite-smectite was not changed by prolonged freshwater treatment. Chlorite-bearing sandstones (Fe-rich chlorite) were reacted with 1M to 10M HCl at temperatures of up to 80 degrees C and for periods of up to 48 hours. Before treatment the chlorites showed typically platy morphologies. After HCl treatment the chlorite grains were coated with an amorphous gel composed of Ca, Cl, and possibly amorphous Si, as determined by EDS analyses on the freshly treated rock surface. Brief washing in water removed this surface coating and revealed apparently unchanged chlorite showing no signs of dissolution or acid attack. However, although the chlorite showed no morphological changes, elemental analysis only detected silicon and oxygen.

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Purpose: To examine the symmetry of corneal changes following near work in the fellow eyes of non-amblyopic myopic anisometropes. Methods: Thirty-four non-amblyopic, myopic anisometropes (minimum 1 D spherical equivalent anisometropia) had corneal topography measured before and after a controlled near work task. Subjects were positioned in a headrest to minimise head movements and read continuous text on a computer monitor for 10 minutes at an angle of 25 degrees downward gaze and an accommodation demand of 2.5 D. Measures of the morphology of the palpebral aperture during primary and downward gaze were also obtained. Results: The more and less myopic eyes exhibited a high degree of interocular symmetry for measures of palpebral aperture morphology during both primary and downward gaze. Following the near work task, fellow eyes also displayed a symmetrical change in superior corneal topography (hyperopic defocus) which correlated with the position of the upper eyelid during downward gaze. Greater changes in the spherical corneal power vector (M) following reading were associated with narrower palpebral aperture during downward gaze (p = 0.07 for more myopic and p = 0.03 for less myopic eyes). A significantly greater change in J0 (an increase in against the rule astigmatism) was observed in the more myopic eyes (-0.04 ± 0.04 D) compared to the less myopic eyes (-0.02 ± 0.06 D) over a 6 mm corneal diameter (p = 0.01). Conclusions: Changes in corneal topography following near work are highly symmetrical between the fellow eyes of myopic anisometropes due to the interocular symmetry of the palpebral aperture. However, the more myopic eye exhibits changes in corneal astigmatism of greater magnitude compared to the less myopic eye.

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The first year of a property degree program is a time to establish threshold concept knowledge to acculturise students into their discipline or professional group. Due to the foundational nature of first year in many property degrees, students are enrolled in large, multi-disciplinary classes. There are several challenges in the delivery of large first year multi-disciplinary units to engage the student in a community of leaning to aid in student retention. Through action based research this study shows how social networking, particularly Facebook, can be used to create a sense of community across large, multi-disciplinary units to illicit ‘real time’ feedback from students and encourage peer to peer learning. This study assesses the benefits of using social media and considers the potential limitations of this medium.

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Recently claims have been made that all universities will in coming decades merge to become just a few mega-institutions offering online degrees to the world. This assumes a degree of literacy with ICT (information and communication technology) amongst potential students, who are often regarded as 'digital natives'. Far from being digital natives, many students have considerable trouble using ICT beyond the ubiquitous Facebook. While some students are computer literate, a substantial proportion lack the skills to prosper under their own devices in an online tertiary education environment. For these students a blended learning experience is needed to develop skills to effectively interact in the virtual environment. This paper presents a case study that specifically examined the ICT capabilities of first-year university students enrolled in the School of Civil Engineering and the Built Environment at Queensland University of Technology (QUT). Empirical data are presented and curriculum strategies articulated to develop ICT skills in university undergraduates.

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The future of the HRM profession depends to at least some extent on the quality of preparation of the next generation of HR professionals. This paper examines bachelor degree programs in HRM and the role of professional associations as influencers of curricula. Some 39% of the 599 AACSB and EQUIS-accredited institutions sampled offer undergraduate degrees in HRM. The programs vary in emphasis on HRM competencies. Unsurprisingly, all include foundation work (perhaps a third of the content) in business management. Grouping degree content by regions globally allows benchmarking of degrees against international trends, along with consideration of the increasingly significant influence on curricula by professional bodies, in preparing the next generation of HRM practitioners to manage in organisations that will require strategic thinking, specialist technical skills, and interpersonal competence.

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Concern to ensure that all children have access to high quality educational experiences in the early years of life has instigated moves to increase qualifications of staff in the childcare workforce, in particular to increase the number of degree qualified teachers. However existing data suggest that work in the childcare sector is viewed less favourably by those undertaking early childhood education degrees. For most, childcare is not a preferred place of employment. This study asked whether a practicum in a childcare setting would improve attitudes to childcare and willingness to consider working in childcare settings. In a study of a cohort of Bachelor of Education (Early Childhood) students, measures of attitudes to childcare and willingness to work in childcare were taken before and after practicum. Additionally students provided accounts of their practicum experiences. Results indicate a trend in which there was a group increase in positive attitudes and willingness to consider work in childcare but considerable individual differences influenced by the quality of the practicum experience. The relationship with, and model provided by, centre directors and the group leader in the practicum class was identified as key influencing factors. Results are discussed in term of models of pedagogical leadership.

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In Australia, few fashion brands have intervened in the design of their products or the systems around their product to tackle environmental pollution and waste. Instead, support of charities (whether social or environmental) has become conflated with sustainability in the eyes of the public.However, three established Australian brands recently put forward initiatives which explicitly tackle the pre-consumer or post-consumer waste associated with their products. In 2011, Billabong, one of the largest surfwear companies in the world, developed a collection of board shorts made from recycled bottles that are also recyclable at end of life. The initiative has been promoted in partnership with Bob Marley’s son Rohan Marley, and the graphics of the board shorts reference the Rastafarian colours and make use of Marley’s song lyrics. In this way, the company has tapped into an aspect of surf culture linked to environmental activism, in which the natural world is venerated. Two mid-market initiatives, by Metalicus and Country Road, each have a social outcome that arguably aligns to the values of their middle-class consumer base. Metalicus is spear-heading a campaign for Australian garment manufacturers to donate their pre consumer waste – fabric off-cuts – to charity Open Family Australia to be manufactured into quilts for the homeless. Country Road has partnered with the Australian Red Cross to implement a recycling scheme in which consumers donate their old Country Road garments in exchange for a Country Road gift voucher. Both strategies, while tackling waste, tell an altruistic story in which the disadvantaged can benefit from the consumption habits of the middle-class. To varying degrees, the initiative chosen by each company feeds into the stories they tell about themselves and about the consumers who purchase their clothing. However, how can we assess the impact of these schemes on waste management in real terms, or indeed the worth of each scheme in the wider context of the fashion system? This paper will assess the claims made by the companies and analyse their efficacy, suggesting that a more nuanced assessment of green claims is required, in which ‘green’ comes in many tonal variations.

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This case-study explores alternative and experimental methods of research data acquisition, through an emerging research methodology, ‘Guerrilla Research Tactics’ [GRT]. The premise is that the researcher develops covert tactics for attracting and engaging with research participants. These methods range between simple analogue interventions to physical bespoke artefacts which contain an embedded digital link to a live, interactive data collecting resource, such as an online poll, survey or similar. These artefacts are purposefully placed in environments where the researcher anticipates an encounter and response from the potential research participant. The choice of design and placement of artefacts is specific and intentional. DESCRIPTION: Additional information may include: the outcomes; key factors or principles that contribute to its effectiveness; anticipated impact/evidence of impact. This case-study assesses the application of ‘Guerrilla Research Tactics’ [GRT] Methodology as an alternative, engaging and interactive method of data acquisition for higher degree research. Extending Gauntlett’s definition of ‘new creative methods… an alternative to language driven qualitative research methods' (2007), this case-study contributes to the existing body of literature addressing creative and interactive approaches to HDR data collection. The case-study was undertaken with Masters of Architecture and Urban Design research students at QUT, in 2012. Typically students within these creative disciplines view research as a taxing and boring process, distracting them from their studio design focus. An obstacle that many students face, is acquiring data from their intended participant groups. In response to these challenges the authors worked with students to develop creative, fun, and engaging research methods for both the students and their research participants. GRT are influenced by and developed from a combination of participatory action research (Kindon, 2008) and unobtrusive research methods (Kellehear, 1993), to enhance social research. GRT takes un-obtrusive research in a new direction, beyond the typical social research methods. The Masters research students developed alternative methods for acquiring data, which relied on a combination of analogue design interventions and online platforms commonly distributed through social networks. They identified critical issues that required action by the community, and the processes they developed focused on engaging with communities, to propose solutions. Key characteristics shared between both GRT and Guerrilla Activism, are notions of political issues, the unexpected, the unconventional, and being interactive, unique and thought provoking. The trend of Guerrilla Activism has been adapted to: marketing, communication, gardening, craftivism, theatre, poetry, and art. Focusing on the action element and examining elements of current trends within Guerrilla marketing, we believe that GRT can be applied to a range of research areas within various academic disciplines.

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This case-study exemplifies a ‘writing movement’, which is currently occurring in various parts of Australia through the support of social media. A concept emerging from the café scene in San Francisco, ‘Shut Up and Write!’ is a meetup group that brings writers together at a specific time and place to write side by side, thus making writing practice, social. This concept has been applied to the academic environment and our case-study explores the positive outcomes in two locations: RMIT University and QUT. We believe that this informal learning practice can be implemented to assist research students in developing academic skills. DESCRIPTION: Please describe your practice as a case study, including its context; challenge addressed; its aims; what it is; and how it supports creative practice PhD students or supervisors. Additional information may include: the outcomes; key factors or principles that contribute to its effectiveness; anticipated impact/evidence of impact. Research students spend the majority of their time outside of formal learning environments. Doctoral candidates enter their degree with a range of experience, knowledge and needs, making it difficult to provide writing assistance in a structured manner. Using a less structured approach to provide writing assistance has been trialled with promising results (Boud, Cohen, & Sampson, 2001; Stracke, 2010; Devenish et al, 2009). Although, semi structured approaches have been developed and examined, informal learning opportunities have received minimal attention. The primary difference of Shut Up and Write! to other writing practices, is that individuals do not engage in any structured activity and they do not share the outcomes of the writing. The purpose of Shut Up and Write! is to transform writing practice from a solitary experience, to a social one. Shut Up and Write! typically takes place outside of formal learning environments, in public spaces such as a café. The structure of Shut Up and Write! sessions is simple: participants meet at a specific time and place, chat for a few minutes, then they Shut Up and Write for a predetermined amount of time. Critical to the success of the sessions, is that there is no critiquing of the writing, and there is no competition or formal exercises. Our case-study examines the experience of two meetup groups at RMIT University and QUT through narrative accounts from participants. These accounts reveal that participants have learned: • Writing/productivity techniques; • Social/cloud software; • Aspects of the PhD; and • ‘Mundane’ dimensions of academic practice. In addition to this, activities such as Shut Up and Write! promote peer to peer bonding, knowledge exchange, and informal learning within the higher degree research experience. This case-study extends the initial work presented by the authors in collaboration with Dr. Inger Mewburn at QPR2012 – Quality in Postgraduate Research Conference, 2012.

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The microstructure of YBa2Cu3O7-delta (Y-123) materials partially-melted in air and quenched from the temperature range 900-1100 degrees C, has been characterized using a combination of X-ray diffractometry, optical microscopy, scanning electron microscopy, electron microprobe analyses, transmission electron microscopy and energy and wave dispersive X-ray spectrometries. The microstructural studies reveal significant changes in the character of the quenched partial-melt as a function of temperature and time before quenching. BaCu2O2 and BaCuO2 are found to co-exist in stoichiometric samples quenched from the temperature range 920-960 degrees C. Under suitable cooling conditions, large pockets of melt cristallize as BaCuO2 with an exsolution of BaCu2O2 in the form of thin plates (approximate to 50-100 nm thick) along facets. Y2BaCuO5 (Y-211) additions are associated with the formation of BaCu2O2 at 1100 degrees C. Preliminary results on the effects of PtO2 and CeO2 additions to Y-123 (and Y-123 with Y-211 additions) show that these enhace the formation of BaCu2O2 at the melting temperature of 1100 degrees C. (C) 1998 Elsevier Science S.A. All rights reserved.