948 resultados para Reveal


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Objective The spondylarthritides (SpA), including ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis, and arthritis associated with inflammatory bowel disease, cause chronic inflammation of the large peripheral and axial joints, eyes, skin, ileum, and colon. Genetic studies reveal common candidate genes for AS, PsA, and Crohn's disease, including IL23R, IL12B, STAT3, and CARD9, all of which are associated with interleukin-23 (IL-23) signaling downstream of the dectin 1 β-glucan receptor. In autoimmune-prone SKG mice with mutated ZAP-70, which attenuates T cell receptor signaling and increases the autoreactivity of T cells in the peripheral repertoire, IL-17–dependent inflammatory arthritis developed after dectin 1–mediated fungal infection. This study was undertaken to determine whether SKG mice injected with 1,3-β-glucan (curdlan) develop evidence of SpA, and the relationship of innate and adaptive autoimmunity to this process. Methods SKG mice and control BALB/c mice were injected once with curdlan or mannan. Arthritis was scored weekly, and organs were assessed for pathologic features. Anti–IL-23 monoclonal antibodies were injected into curdlan-treated SKG mice. CD4+ T cells were transferred from curdlan-treated mice to SCID mice, and sera were analyzed for autoantibodies. Results After systemic injection of curdlan, SKG mice developed enthesitis, wrist, ankle, and sacroiliac joint arthritis, dactylitis, plantar fasciitis, vertebral inflammation, ileitis resembling Crohn's disease, and unilateral uveitis. Mannan triggered spondylitis and arthritis. Arthritis and spondylitis were T cell– and IL-23–dependent and were transferable to SCID recipients with CD4+ T cells. SpA was associated with collagen- and proteoglycan-specific autoantibodies. Conclusion Our findings indicate that the SKG ZAP-70W163C mutation predisposes BALB/c mice to SpA, resulting from innate and adaptive autoimmunity, after systemic β-glucan or mannan exposure.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Ambient media architecture can provide place-based collaborative learning experiences and pathways for social interactions that would not be otherwise possible. This paper is concerned with ways of enhancing peer-to-peer learning affordances in library spaces; how can the library facilitate the community of library users to learn from each other? We report on the findings of a study that employed a participatory design method where participants were asked to reflect and draw places, social networks, and activities that they use to work (be creative, productive), play (have fun, socialize, be entertained), and learn (acquire new information, knowledge, or skills). The results illustrate how informal learning – learning outside the formal education system – is facilitated by a personal selection of physical and socio-cultural environments, as well as online tools, platforms, and networks. This paper sheds light on participants’ individually curated ecologies of their work, play, and learning related networks and the hybrid (physical and digital) nature of these places. These insights reveal opportunities for ambient media architecture to increase awareness of and connections between people’s hybrid personal learning environments.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The author aims at developing a better understanding of unstructured strategic decision making processes and the conditions for achieving successful decision outcomes. Specifically he investigates the processes used to make CRE (Corporate Real Estate) decisions. To reveal the fundamental differences between CRE decision-making in practice and the prescriptive ‘best practice’ advocated in the CRE literature, a study of seven leading Italian management consulting firms is undertaken addressing the aspects of content and process of decisions. This research makes its primary contribution by identifying the importance and difficulty of finding the right balance between problem complexity, process richness and cohesion to ensure a decision-making process that is sufficiently rich and yet quick enough to deliver a prompt outcome. While doing so, the study also provides more empirical evidence to some of the most established theories of decision-making, while reinterpreting their mono-dimensional arguments in a multi-dimensional model of successful decision-making.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Dual-mode vibration of nanowires has been reported experimentally through actuation of the nanowire at its resonance frequency, which is expected to open up a variety of new modalities for the NEMS that could operate in the nonlinear regime. In the present work, we utilize large scale molecular dynamics simulations to investigate the dual-mode vibration of <110> Ag nanowires with triangular, rhombic and truncated rhombic cross-sections. By incorporating the generalized Young-Laplace equation into Euler-Bernoulli beam theory, the influence of surface effects on the dual-mode vibration is studied. Due to the different lattice spacing in principal axes of inertia of the {110} atomic layers, the NW is also modeled as a discrete system to reveal the influence from such specific atomic arrangement. It is found that the <110> Ag NW will under a dual-mode vibration if the actuation direction is deviated from the two principal axes of inertia. The predictions of the two first mode natural frequencies by the classical beam model appear underestimated comparing with the MD results, which are found to be enhanced by the discrete model. Particularly, the predictions by the beam theory with the contribution of surface effects are uniformly larger than the classical beam model, which exhibit better agreement with MD results for larger cross-sectional size. However, for ultrathin NWs, current consideration of surface effects is still experiencing certain inaccuracy. In all, for all different cross-sections, the inclusion of surface effects is found to reduce the difference between the two first mode natural frequencies. This trend is observed consistent with MD results. This study provides a first comprehensive investigation on the dual-mode vibration of <110> oriented Ag NWs, which is supposed to benefit the applications of NWs that acting as a resonating beam.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

How do you identify "good" teaching practice in the complexity of a real classroom? How do you know that beginning teachers can recognise effective digital pedagogy when they see it? How can teacher educators see through their students’ eyes? The study in this paper has arisen from our interest in what pre-service teachers “see” when observing effective classroom practice and how this might reveal their own technological, pedagogical and content knowledge. We asked 104 pre-service teachers from Early Years, Primary and Secondary cohorts to watch and comment upon selected exemplary videos of teachers using ICT (information and communication technologies) in Science. The pre-service teachers recorded their observations using a simple PMI (plus, minus, interesting) matrix which were then coded using the SOLO Taxonomy to look for evidence of their familiarity with and judgements of digital pedagogies. From this, we determined that the majority of preservice teachers we surveyed were using a descriptive rather than a reflective strategy, that is, not extending beyond what was demonstrated in the teaching exemplar or differentiating between action and purpose. We also determined that this method warrants wider trialling as a means of evaluating students’ understandings of the complexity of the digital classroom.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

F-actin remodelling is essential for a wide variety of cell processes. It is important in exocytosis, where F-actin coats fusing exocytic granules. The purpose of these F-actin coats is unknown. They may be important in stabilizing the fused granules, they may play a contractile role and promote expulsion of granule content and finally may be important in endocytosis. To elucidate these functions of F-actin remodelling requires a reliable method to visualize F-actin dynamics in living cells. The recent development of Lifeact-EGFP transgenic animals offers such an opportunity. Here, we studied the characteristics of exocytosis in pancreatic acinar cells obtained from the Lifeact-EGFP transgenic mice. We show that the time-course of agonist-evoked exocytic events and the kinetics of each single exocytic event are the same for wild type and Lifeact-EGFP transgenic animals. We conclude that Lifeact-EGFP animals are a good model to study of exocytosis and reveal that F-actin coating is dependent on the de novo synthesis of F-actin and that development of actin polymerization occurs simultaneously in all regions of the granule. Our insights using the Lifeact-EGFP mice demonstrate that F-actin coating occurs after granule fusion and is a granule-wide event.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The Australian Association for Research in Education (AARE) by promoting the conference theme has identified a need to be more proactive to ensure growth in the number of educational researchers. Within the Higher Education sector there are a number of methods used to encourage interest in a particular area, and these include policy, funding, sponsorship, employment and scholarships. There are three types of employment for academics: Research, Lecturing and Teaching and Learning and two types of scholarships: either students self-identify the topic or topics are targeted with associated funding. The aim of this study is to review the academic positions and targeted scholarships of Australian Universities and research organisations gathered from advertisements in a national newspaper. This will establish a baseline of recent practice from July to December, 2006 and identify opportunities for researchers in all Disciplines and specifically in education. Results reveal the two main groups for academics are Research and Lecturing, with a small number in Teaching and Learning. Although the Education Discipline is well represented overall (3rd in 12 Disciplines after Health and Science) in terms of research opportunities education then moves to 10th position. A further significant finding is the highly contractual nature of research versus the more stable, tenured environment for lecturing. There are a number of implications arising from this short study. Firstly, the Discipline of Education as a targeted area for research alone is significantly under-represented in the advertised positions but is well represented in lecturing where the role always requires teaching and research. Thus it seems the amount of time devoted to research by academics in the education Discipline is significantly lower than for health or science. Secondly, there are few industry/Government targeted scholarships in the education Discipline therefore any growth in numbers of educational researchers through postgraduate study is not expanded by funding to meet identified needs. In conclusion AARE, an association interested in promoting the growth of educational research, has an obvious need to encourage and review the outcomes of this study and perhaps adopt some of the successful strategies employed by other Disciplines to improve the opportunities for educational researchers in the future.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Recent analyses of population data reveal that obesity rates continue to rise, and are projected to reach unprecedented levels over the next decade 1. Despite concerted efforts to impede obesity progression, as of today, weight loss and weight maintenance strategies remain at best partially successful endeavours. Regardless of the observation that weight loss strategies can produce significant weight loss 2 and substantial improvements of the determinants of the metabolic risk profile 3, 4, it is clear that actual weight loss tends to be lower than the anticipated weight loss, and most individuals who achieve weight loss will likely regain some weight 5 and even overshoot 6 their pre-intervention body weight. As such, an improved understanding of the factors that contribute to lower than expected weight loss, and poor weight maintenance would improve the effectiveness of weight loss interventions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Memoir, 288 pages. An account of journeys made by the author from Australia to Iceland as a way of interrogating notions of cultural belonging, family, and homecoming. "In 1990, Kári Gíslason travelled to Iceland to meet his father for the first time. What he finds is not what he expected. Born from a secret liaison between a British mother and an Icelandic father, Kári Gíslason was the subject of a promise – a promise elicited from his father to not reveal his identity. The Icelandic city of Reykjavík, where Kári was born, was also home to his father and his father’s wife and five children – none of whom knew of Kári’s existence. Moving regularly between Iceland and Australia, he grew up aware of his father’s identity, but understanding that it was the subject of a secret pact between his parents. At the age of 27, he makes a decision to break the pact and contacts his father’s other family. What follows, and what leads him there, makes for a riveting journey over landscapes, time and memory. Kári travels from the freezing cold winters of Iceland to the shark net at Sydney’s Balmoral, an unsettled life in the English countryside and the harsh yellow summer of Brisbane, and back again. He traces the steps of his mother who answered an ad in The Times for an English-speaking secretary in 1970 and found herself in Iceland among the ‘Army of Foreign Secretaries’, and in the arms of a secret lover. Iceland becomes the substitute for the father Kári never really knew as he discovers the meaning of ‘home’ and closes the circle of his own fatherless life."-- publisher website

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background: Panicum streak virus (PanSV; Family Geminiviridae; Genus Mastrevirus) is a close relative of Maize streak virus (MSV), the most serious viral threat to maize production in Africa. PanSV and MSV have the same leafhopper vector species, largely overlapping natural host ranges and similar geographical distributions across Africa and its associated Indian Ocean Islands. Unlike MSV, however, PanSV has no known economic relevance. Results: Here we report on 16 new PanSV full genome sequences sampled throughout Africa and use these together with others in public databases to reveal that PanSV and MSV populations in general share very similar patterns of genetic exchange and geographically structured diversity. A potentially important difference between the species, however, is that the movement of MSV strains throughout Africa is apparently less constrained than that of PanSV strains. Interestingly the MSV-A strain which causes maize streak disease is apparently the most mobile of all the PanSV and MSV strains investigated. Conclusion: We therefore hypothesize that the generally increased mobility of MSV relative to other closely related species such as PanSV, may have been an important evolutionary step in the eventual emergence of MSV-A as a serious agricultural pathogen. The GenBank accession numbers for the sequences reported in this paper are GQ415386-GQ415401. © 2009 Varsani et al; licensee BioMed Central Ltd.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Barmah Forest virus (BFV) disease is one of the most widespread mosquito-borne diseases in Australia. The number of outbreaks and the incidence rate of BFV in Australia have attracted growing concerns about the spatio-temporal complexity and underlying risk factors of BFV disease. A large number of notifications has been recorded continuously in Queensland since 1992. Yet, little is known about the spatial and temporal characteristics of the disease. I aim to use notification data to better understand the effects of climatic, demographic, socio-economic and ecological risk factors on the spatial epidemiology of BFV disease transmission, develop predictive risk models and forecast future disease risks under climate change scenarios. Computerised data files of daily notifications of BFV disease and climatic variables in Queensland during 1992-2008 were obtained from Queensland Health and Australian Bureau of Meteorology, respectively. Projections on climate data for years 2025, 2050 and 2100 were obtained from Council of Scientific Industrial Research Organisation. Data on socio-economic, demographic and ecological factors were also obtained from relevant government departments as follows: 1) socio-economic and demographic data from Australian Bureau of Statistics; 2) wetlands data from Department of Environment and Resource Management and 3) tidal readings from Queensland Department of Transport and Main roads. Disease notifications were geocoded and spatial and temporal patterns of disease were investigated using geostatistics. Visualisation of BFV disease incidence rates through mapping reveals the presence of substantial spatio-temporal variation at statistical local areas (SLA) over time. Results reveal high incidence rates of BFV disease along coastal areas compared to the whole area of Queensland. A Mantel-Haenszel Chi-square analysis for trend reveals a statistically significant relationship between BFV disease incidence rates and age groups (ƒÓ2 = 7587, p<0.01). Semi-variogram analysis and smoothed maps created from interpolation techniques indicate that the pattern of spatial autocorrelation was not homogeneous across the state. A cluster analysis was used to detect the hot spots/clusters of BFV disease at a SLA level. Most likely spatial and space-time clusters are detected at the same locations across coastal Queensland (p<0.05). The study demonstrates heterogeneity of disease risk at a SLA level and reveals the spatial and temporal clustering of BFV disease in Queensland. Discriminant analysis was employed to establish a link between wetland classes, climate zones and BFV disease. This is because the importance of wetlands in the transmission of BFV disease remains unclear. The multivariable discriminant modelling analyses demonstrate that wetland types of saline 1, riverine and saline tidal influence were the most significant risk factors for BFV disease in all climate and buffer zones, while lacustrine, palustrine, estuarine and saline 2 and saline 3 wetlands were less important. The model accuracies were 76%, 98% and 100% for BFV risk in subtropical, tropical and temperate climate zones, respectively. This study demonstrates that BFV disease risk varied with wetland class and climate zone. The study suggests that wetlands may act as potential breeding habitats for BFV vectors. Multivariable spatial regression models were applied to assess the impact of spatial climatic, socio-economic and tidal factors on the BFV disease in Queensland. Spatial regression models were developed to account for spatial effects. Spatial regression models generated superior estimates over a traditional regression model. In the spatial regression models, BFV disease incidence shows an inverse relationship with minimum temperature, low tide and distance to coast, and positive relationship with rainfall in coastal areas whereas in whole Queensland the disease shows an inverse relationship with minimum temperature and high tide and positive relationship with rainfall. This study determines the most significant spatial risk factors for BFV disease across Queensland. Empirical models were developed to forecast the future risk of BFV disease outbreaks in coastal Queensland using existing climatic, socio-economic and tidal conditions under climate change scenarios. Logistic regression models were developed using BFV disease outbreak data for the existing period (2000-2008). The most parsimonious model had high sensitivity, specificity and accuracy and this model was used to estimate and forecast BFV disease outbreaks for years 2025, 2050 and 2100 under climate change scenarios for Australia. Important contributions arising from this research are that: (i) it is innovative to identify high-risk coastal areas by creating buffers based on grid-centroid and the use of fine-grained spatial units, i.e., mesh blocks; (ii) a spatial regression method was used to account for spatial dependence and heterogeneity of data in the study area; (iii) it determined a range of potential spatial risk factors for BFV disease; and (iv) it predicted the future risk of BFV disease outbreaks under climate change scenarios in Queensland, Australia. In conclusion, the thesis demonstrates that the distribution of BFV disease exhibits a distinct spatial and temporal variation. Such variation is influenced by a range of spatial risk factors including climatic, demographic, socio-economic, ecological and tidal variables. The thesis demonstrates that spatial regression method can be applied to better understand the transmission dynamics of BFV disease and its risk factors. The research findings show that disease notification data can be integrated with multi-factorial risk factor data to develop build-up models and forecast future potential disease risks under climate change scenarios. This thesis may have implications in BFV disease control and prevention programs in Queensland.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

For decades there have been two young driver concepts: the „young driver problem‟ where the driver cohort represents a key problem for road safety; and the „problem young driver‟ where a sub-sample of drivers represents the greatest road safety problem. Given difficulties associated with identifying and then modifying the behaviour of the latter group, broad countermeasures such as graduated driver licensing (GDL) have generally been relied upon to address the young driver problem. GDL evaluations reveal general road safety benefits for young drivers, yet they continue to be overrepresented in fatality and injury statistics. Therefore it is timely for researchers revisit the problem young driver concept to assess its potential countermeasure implications. Personal characteristics, behaviours and attitudes of 378 Queensland novice drivers aged 17-25 years were explored during their pre-, Learner and Provisional 1 (intermediate) licence as part of a larger longitudinal research project. Self-reported risky driving was measured by the Behaviour of Young Novice Drivers Scale (BYNDS), and five subscale scores were used to cluster the drivers into three groups (high risk n = 49, medium risk n = 163, low risk n = 166). High risk „problem young‟ drivers were characterised by self-reported pre-Licence driving, unsupervised Learner driving, and speeding, driving errors, risky driving exposure, crash involvement, and offence detection during the Provisional period. Medium risk drivers were also characterised by more risky road use behaviours than the low risk group. Interestingly problem young drivers appear to have some insight into their high-risk driving, and they report significantly greater intentions to bend road rules in future driving. The results suggest that in addition to broad countermeasures such as GDL which target the young driver problem, tailored intervention efforts may need to target problem young drivers. Driving behaviours and crash-involvement could be used to identify these drivers as pre-intervention screening measures.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Background Information practice is an emerging area of research that seeks to reveal how people learn to connect with the complex multimodal information landscapes that informs their ability to make decisions. Previous research has identified that people with end stage kidney disease (ESKD) tend to adopt a ‘received’ or ‘engaged’ view of information but little is known about the activities of information practice. Objectives This research project sought to identify the: i) information-related activities; and ii) how information is used. Methods Using a constructivist qualitative methodology, ten people with ESKD living in a large metropolitan city were purposively selected and interviewed. Data was subject to thematic analysis by researchers from nursing and information science. Saturation of themes was achieved. Results Participants were between 38 and 72 years, had been receiving kidney replacement therapy from 2 weeks to 31 years. Eight participants reported having access to the internet but none participated in chat rooms. The activities were conceptualized into themes as listening, seeking, searching, sharing and observing. These activities enabled people to create, reflect on and evaluate the information needed to inform their decision-making Conclusion/Application to Clinical Practice The information practice research approach will enable a better understanding of the underlying relationship between information, knowledge and experience to be better understood. For renal nurses who are involved in patient education being able to recognise the way people use information will assist in individualizing educational sessions and tailoring teaching strategies to make it more meaningful.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

We examine the corporate governance environment of smaller listed Australian firms to investigate the factors that determine how firms respond to recommendations contained in corporate governance codes. We group corporate governance recommendations into three distinct categories and argue that differences in adoption costs between categories, together with firm specific factors, determine a firm’s decision to conform with the recommendation or to explain the reasons for non-conformance. Analysis of the conformance by smaller firms with governance recommendations highlights substantial differences in adoption rates between categories of recommendations. Our results also reveal that the cost of adopting specific recommendations, together with profitability, external audit quality, and ownership dispersion, jointly explain a firm’s decision to ‘comply or explain’. This study provides insights for policy makers and regulators regarding the appropriateness of corporate governance recommendations for smaller firms

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The study of matrices of rare Type 4 carbonaceous chondrites can reveal important information on parent body rnetamorp~ic processes and provide a comparison with processes on parent bodies of ordinary chc-idrites. Reflectance spectra (Tholen, 1984) from the two largest asteroids in the asteroid belt, Ceres and Pallas, suggest that they may be metamorphosed carbonaceous chondrites. These two asteroids constitute - onethird of the mass in the asteroid belt implying that type 4-6 carbonaceous chondrites are poorly represented in the meteorite collection and may be of considerable importance. The matrix of the C4 chondrite Karoonda has been investigated using a JEOL 2000FX analytical electron microscope (AEM) with an attached Tracor-Northem TN5500 energy dispersive spectrometer (EDS). In previous studies (Scott and Taylor, 1985; Fitzgerald, 1979; Van Schmus, 1969), the petrography of the Karoonda matrix has been described as consisting largely of coarse-grained (50-200 urn in size) olivine and plagioclase (20-100 um in size), associated with micrometer sized magnetite and rare sulphides. AEM observations on matrix show that in addition to these large grains, there is a significant fraction (10 vol%) of interstitial fine grained phases « 5 urn). The mineralogy of these fine-grained phases differs in some respects from that of the coarser-grained matrix identified by optical and SEM techniques (Scott and Taylor, 1985; Fitzgerald, 1979; Van Schmus, 1969). I~ particular crystals of two compositionally distinct pyroxenes « 2 urn in size) have been identified which have not been previously observed in Karoonda by other analytical techniques. Thin film microanalyses (Mackinnon et al., 1986) of these two pyroxenes indicate compositions consistent with augite and low-Ca pyroxene (- Fs27). Fine-grained anhedral olivine « 2 urn size) is the most abundant phase with composition -Fa29' This composition is essentially indistinguishable from that determined for coarser-grained matrix olivines using an electron microprobe (Scott and Taylor, 1985; Fitzgerald, 1979; Van Schmus, 1969). All olivines are associated with subhedral magnetites « 1 urn size) which contain significant Cr (- 2%) and Al (- 1%) as was also noted for larger sized Karoonda magnetites by Delaney et al. (1985). It has recently been suggested (Burgess et al., 1987) on the basis of sulphur release profiles for S-isotope analyses of Karoonda that CaS04 (anhydrite) may be present. However, no sulphate phase has, as yet, been identified in the matrix of Karoonda. Low magnification contrast images suggest that Karoonda may have a significant porosity within the fine-grained matrix fraction. Most crystals are anhedral and do not show evidence for significant compaction. Individual grains often show single point contact with other grains which result in abundant intergranular voids. These voids frequently contain epoxy which was used as part of the specimen preparation procedure due to the friable nature of the bulk sample.