388 resultados para Slater, Michelle


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We examined the structure and extent of genetic diversity in intrahost populations of Ross River virus (RRV) in samples from six human patients, focusing on the nonstructural (nsP3) and structural (E2) protein genes. Strikingly, although the samples were collected from contrasting ecological settings 3,000 kilometers apart in Australia, we observed multiple viral lineages in four of the six individuals, which is indicative of widespread mixed infections. In addition, a comparison with previously published RRV sequences revealed that these distinct lineages have been in circulation for at least 5 years, and we were able to document their long-term persistence over extensive geographical distances

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Visual adaptation regulates contrast sensitivity during dynamically changing light conditions (Crawford, 1947; Hecht, Haig & Chase, 1937). These adaptation dynamics are unknown under dim (mesopic) light levels when the rod (R) and long (L), medium (M) and short (S) wavelength cone photoreceptor classes contribute to vision via interactions in shared non-opponent Magnocellular (MC), chromatically opponent Parvocellular (PC) and Koniocellular (KC) visual pathways (Dacey, 2000). This study investigated the time-course of adaptation and post-receptoral pathways mediating receptor specific rod and cone interactions under mesopic illumination. A four-primary photostimulator (Pokorny, Smithson & Quinlan, 2004) was used to independently control the activity of the four photoreceptor classes and their post-receptoral visual athways in human observers. In the first experiment, the contrast sensitivity and time-course of visual adaptation under mesopic illumination were measured for receptoral (L, S, R) and post-receptoral (LMS, LMSR, L-M) stimuli. An incremental (Rapid-ON) sawtooth conditioning pulse biased detection to ON-cells within the visual pathways and sensitivity was assayed relative to pulse onset using a briefly presented incremental probe that did not alter adaptation. Cone.Cone interactions with luminance stimuli (L cone, LMS, LMSR) reduced sensitivity by 15% and the time course of recovery was 25± 5ms-1 (μ ± SEM). PC mediated (+L-M) chromatic stimuli sensitivity loss was less (8%) than for luminance and recovery was slower (μ = 2.95 ± 0.05 ms-1), with KC mediated (S cone) chromatic stimuli showing a high sensitivity loss (38%) and the slowest recovery time (1.6 ± 0.2 ms-1). Rod-Rod interactions increased sensitivity by 20% and the time course of recovery was 0.7 ± 0.2 ms-1 (μ ± SD). Compared to these interaction types, Rod-Cone interactions reduced sensitivity to a lesser degree (5%) and showed the fastest recovery (μ = 43 ± 7 ms-1). In the second experiment, rod contribution to the magnocellular, parvocellular and koniocellular post-receptoral pathways under mesopic illumination was determined as a function of incremental stimulus duration and waveform (rectangular; sawtooth) using a rod colour match procedure (Cao, Pokorny & Smith, 2005; Cao, Pokorny, Smith & Zele, 2008a). For a 30% rod increment, a cone match required a decrease in [L/(L+M)] and an increase in [L+M] and [S/(L+M)], giving a greenish-blue and brighter appearance for probe durations of 75 ms or longer. Probe durations less than 75 ms showed an increase in [L+M] and no change in chromaticity [L/(L+M) or S/(L+M)], uggesting mediation by the MC pathway only for short duration rod stimuli. s We advance previous studies by determining the time-course and nature of photoreceptor specific retinal interactions in the three post-receptoral pathways under mesopic illumination. In the first experiment, the time-course of adaptation for ON cell processing was determined, revealing opponent cell facilitation in chromatic PC and KC pathways. The Rod-Rod and Rod-Cone data identify previously unknown interaction types that act to maintain contrast sensitivity during dynamically changing light conditions and improve the speed of light adaptation under mesopic light levels. The second experiment determined the degree of rod contribution to the inferred post-eceptoral pathways as a function of the temporal properties of the rod signal. r The understanding of the mechanisms underlying interactions between photoreceptors under mesopic illumination has implications for the study of retinal disease. Visual function has been shown to be reduced in persons with age-related maculopathy (ARM) risk genotypes prior to clinical signs of the disease (Feigl, Cao, Morris & Zele, 2011) and disturbances in rod-mediated adaptation have been shown in early phases of ARM (Dimitrov, Guymer, Zele, Anderson & Vingrys, 2008; Feigl, Brown, Lovie-Kitchin & Swann, 2005). Also, the understanding of retinal networks controlling vision enables the development of international lighting standards to optimise visual performance nder dim light levels (e.g. work-place environments, transportation).

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Objective Factors associated with the development of hallux valgus (HV) are multifactorial and remain unclear. The objective of this systematic review and meta-analysis was to investigate characteristics of foot structure and footwear associated with HV. Design Electronic databases (Medline, Embase, and CINAHL) were searched to December 2010. Cross-sectional studies with a valid definition of HV and a non-HV comparison group were included. Two independent investigators quality rated all included papers. Effect sizes and 95% confidence intervals (CIs) were calculated (standardized mean differences (SMDs) for continuous data and risk ratios (RRs) for dichotomous data). Where studies were homogeneous, pooling of SMDs was conducted using random effects models. Results A total of 37 papers (34 unique studies) were quality rated. After exclusion of studies without reported measurement reliability for associated factors, data were extracted and analysed from 16 studies reporting results for 45 different factors. Significant factors included: greater first intermetatarsal angle (pooled SMD = 1.5, CI: 0.88–2.1), longer first metatarsal (pooled SMD = 1.0, CI: 0.48–1.6), round first metatarsal head (RR: 3.1–5.4), and lateral sesamoid displacement (RR: 5.1–5.5). Results for clinical factors (e.g., first ray mobility, pes planus, footwear) were less conclusive regarding their association with HV. Conclusions Although conclusions regarding causality cannot be made from cross-sectional studies, this systematic review highlights important factors to monitor in HV assessment and management. Further studies with rigorous methodology are warranted to investigate clinical factors associated with HV.

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Despite an ostensibly technology-driven society, the ability to communicate orally continues to feature as an essential ability for students at school and university, as it is for graduates in the workplace. Pedagogically, one rationale is that the need to develop effective oral communication skills is tied to life-long learning which includes successful participation in future work-related tasks. One tangible way that educators have assessed proficiency in the area of communication is through prepared oral presentations. While much of the literature uses the terms 'oral communication' and 'oral presentation' interchangeably, some writers question the role more formal presentations play in the overall development of oral communication skills. However, such formal speaking tasks continue to be a recognised assessment practice in both the secondary school and academy, and, therefore, worthy of further investigation. Adding to the discussion, this thesis explores the knowledge and skills students bring into the academy from previous educational experiences. It examines some of the teaching and assessment methods used in secondary schools to develop oral communication skills through the use of formal oral presentations. Specifically, it investigates criterion-referenced assessment sheets and how these tools are used as a form of instruction, as well as their role and effectiveness in the evaluation of student ability. The focus is on the student's perspective and includes 12 semi-structured interviews with school students. The purpose of this thesis is to explore key thematics underpinning oral communication and to identify tensions between expectations and practice. While acknowledging the breadth and depth of material available under the heading of 'communication theory', this study specifically draws on an expanded view of the rhetorical tradition to fully interrogate the assumptions supporting the practice of assessing oral presentations. Finally, this thesis recommends reconnecting with an updated understanding of rhetoric as a way of assisting in the development of expressive, articulate and discerning communicators.

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There are an increasing number of compression systems available for treatment of venous leg ulcers and limited evidence on the relative effectiveness of these systems. The purpose of this study was to conduct a randomised controlled trial to compare the effectiveness of a 4-layer compression bandage system with Class 3 compression hosiery on healing and quality of life in patients with venous leg ulcers. Data were collected from 103 participants on demographics, health, ulcer status, treatments, pain, depression and quality of life for 24 weeks. After 24 weeks, 86% of the 4-layer bandage group and 77% of the hosiery group were healed (p=0.24). Median time to healing for the bandage group was 10 weeks, in comparison to 14 weeks for the hosiery group (p=0.018). Cox proportional hazards regression found participants in the 4-layer system were 2.1 times (95% CI 1.2–3.5) more likely to heal than those in hosiery, while longer ulcer duration, larger ulcer area and higher depression scores significantly delayed healing. No differences between groups were found in quality of life or pain measures. Findings indicate these systems were equally effective in healing patients by 24 weeks, however a 4-layer system may produce a more rapid response.

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A quantitative, quasi-experimental study of the effectiveness of computer-based scientific visualizations for concept learning on the part of Year 11 physics students (n=80) was conducted in six Queensland high school classrooms. Students’ gender and academic ability were also considered as factors in relation to the effectiveness of teaching with visualizations. Learning with visualizations was found to be equally effective as learning without them for all students, with no statistically significant difference in outcomes being observed for the group as a whole or on the academic ability dimension. Male students were found to learn significantly better with visualizations than without, while no such effect was observed for female students. This may give rise to some concern for the equity issues raised by introducing visualizations. Given that other research shows that students enjoy learning with visualizations and that their engagement with learning is enhanced, the finding that the learning outcomes are the same as for teaching without visualizations supports teachers’ use of visualizations.

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Parkinson’s disease (PD) is a progressive, chronic neurodegenerative disorder for which there is no known cure. Physical exercise programs may be used to assist with the physical management of PD. Several studies have demonstrated that community based physical therapy programs are effective in reducing physical aspects of disability among people with PD. While multidisciplinary therapy interventions may have the potential to reduce disability and improve the quality of life of people with PD, there is very limited clinical trial evidence to support or refute the use of a community based multidisciplinary or interdisciplinary programs for people with PD. A two group randomized trial is being undertaken within a community rehabilitation service in Brisbane, Australia. Community dwelling adults with a diagnosis of Idiopathic Parkinson’s disease are being recruited. Eligible participants are randomly allocated to a standard exercise rehabilitation group program or an intervention group which incorporates physical, cognitive and speech activities in a multi-tasking framework. Outcomes will be measured at 6-week intervals for a period of six months. Primary outcome measures are the Montreal Cognitive Assessment (MoCA) and the Timed Up and Go (TUG) cognitive test. Secondary outcomes include changes in health related quality of life, communication, social participation, mobility, strength and balance, and carer burden measures. This study will determine the immediate and long-term effectiveness of a unique multifocal, interdisciplinary, dual-tasking approach to the management of PD as compared to an exercise only program. We anticipate that the results of this study will have implications for the development of cost effective evidence based best practice for the treatment of people with PD living in the community.

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This paper describes a capacity building process undertaken within the HIV/AIDS prevention project of the Adventist Development and Relief Agency (ADRA) in the Solomon Islands. ADRA HIV/AIDS has recently reoriented its project structure, moving beyond its awareness raising approach to incorporate health promotion frameworks, theories, strategies and assumptions. These have been used to inform project practice in project planning, delivery and evaluation. This paper shares what has worked and not worked in the capacity building process, including a project evaluation of the initial HIV/AIDS awareness raising project and the application of a number of capacity building strategies, including utilising a volunteer Australian Youth Ambassador for Development (AYAD) funded by the Australian Agency for International Development (AusAID). Existing and new projects are outlined. The underlying theme is that any capacity building exercise must include structural support (e.g. management, national frameworks) to ensure the incorporation of new initiatives and approaches. With time this enables ownership by counterparts and external partnerships to develop. The presence of an AYAD volunteer has been an effective strategy to achieve this. Reflections from the evaluators, the AYAD volunteer and the HIV/AIDS team are included.

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Introduction and Methods: This study compared changes in myokine and myogenic genes following resistance exercise (3 sets of 12 repetitions of maximal unilateral knee extension) in 20 elderly men (67.8 ± 1.0 years) and 15 elderly women (67.2 ± 1.5 years). Results: Monocyte chemotactic protein (MCP)-1, macrophage inhibitory protein (MIP)-1β, interleukin (IL)-6 and MyoD mRNA increased significantly (P < 0.05), whereas myogenin and myostatin mRNA decreased significantly after exercise in both groups. Macrophage-1 (Mac-1) and MCP-3 mRNA did not change significantly after exercise in either group. MIP-1β, Mac-1 and myostatin mRNA were significantly higher before and after exercise in men compared with women. In contrast, MCP-3 and myogenin mRNA were significantly higher before and after exercise in the women compared with the men. Conclusions: In elderly individuals, gender influences the mRNA expression of certain myokines and growth factors, both at rest and after resistance exercise. These differences may influence muscle regeneration following muscle injury

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Objective: The aim of the study is to explore school nurses’ experience of health education. Design: A qualitative approach; phenomenology was used to answer the question. Method: Sixteen participants were recruited through purposeful and snowball sampling. Participants undertook an audio-recorded interview which was transcribed and analysed. Results: Five themes represent school nurses’ experience of health education. Within these five themes, three issues were identified by the participants as having a negative impact on their experience of health education. These were: (1) feeling unwanted by the school; (2) not supported by the school hierarchy; and (3) a lack of role definition. Conclusion: These three issues provide important insight into school nurses’ experience of health education and have implications for other school nurses and professionals in the school environment.

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Background Hallux valgus (HV) is a very common deformity of the first metatarsophalangeal joint that often requires surgical correction. However, the association between structural HV deformity and related foot pain and disability is unclear. Furthermore, no previous studies have investigated concerns about appearance and difficulty with footwear in a population with HV not seeking surgical correction. The aim of this cross-sectional study was to investigate foot pain, functional limitation, concern about appearance and difficulty with footwear in otherwise healthy adults with HV compared to controls. Methods Thirty volunteers with HV (radiographic HV angle >15 degrees) and 30 matched controls were recruited for this study (50 women, 10 men; mean age 44.4 years, range 20 to 76 years). Differences between groups were examined for self-reported foot pain and disability, satisfaction with appearance, footwear difficulty, and pressure-pain threshold at the first metatarsophalangeal joint. Functional measures included balance tests, walking performance, and hallux muscle strength (abduction and plantarflexion). Mean differences (MD) and 95% confidence intervals (CI) were calculated. Results All self-report measures showed that HV was associated with higher levels of foot pain and disability and significant concerns about appearance and footwear (p < 0.001). Lower pressure-pain threshold was measured at the medial first metatarsophalangeal joint in participants with HV (MD = -133.3 kPa, CI: -251.5 to -15.1). Participants with HV also showed reduced hallux plantarflexion strength (MD = -37.1 N, CI: -55.4 to -18.8) and abduction strength (MD = -9.8 N, CI: -15.6 to -4.0), and increased mediolateral sway when standing with both feet with eyes closed (MD = 0.34 cm, CI: 0.04 to 0.63). Conclusions These findings show that HV negatively impacts on self-reported foot pain and function, and concerns about foot appearance and footwear in otherwise healthy adults. There was also evidence of impaired hallux muscle strength and increased postural sway in HV subjects compared to controls, although general physical functioning and participation in physical activity were not adversely affected.

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University can be a psychologically distressing place for students, particularly those studying law. Legal academics have been concerned about this for some time. In the United States, in particular, it has been found that symptoms of psychological distress rise signifi cantly for students in their fi rst year of law (compared to levels in the general population at that time), and persist throughout the degree to post-graduation. Recognised symptoms include depression, obsessive compulsive behaviour, feelings of inadequacy and inferiority, anxiety, hostility, paranoia, and social alienation. Many students experience law school as an isolating, adversarial and competitive environment, which impacts negatively on their values and motivation...