927 resultados para marginal likelihood


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The Guide contains the distilled findings from a major, two-year research project to explore those factors considered by industry practitioners to be critical to the successful adoption of ICT, both within their firms and between their firms and their trading partners. In the context of this project Critical Success Factors (CSFs) have been defined as, “Those things that absolutely, positively must be attended to in order to maximise the likelihood of a successful outcome for the stakeholder, defined in the stakeholder’s terms.” The guide includes: o Perceived benefits of ICT use across the subcontractors’ sector o Types and levels of ICT used across the sector o Self-assessment tool o CSFs for medium- and high-level ICT users, including o Best Practice Profiles o Action Statements o Barriers to ICT use for low-level users o Action Statements The material contained in this Guide has been generated following a number of principles: o For a given situation there is not a single ‘right answer’, but a number of solutions that have to be evaluated using a range of relevant factors. o As there are as many solutions as there are ‘solvers’, factors for evaluation will ‘emerge’ from collective wisdom.

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Within nursing, there is a strong demand for high-quality, cost-effective clinical education experiences that facilitate student learning in the clinical setting The clinical learning environment (CLE) is the interactive network of forces within the clinical setting that influence the students'clinical learning outcomes The identification of factors that characterize CLE could lead to strategies that foster the factors most predictive of desirable student learning outcomes and ameliorate those which may have a negative impact on student outcomes The CLE scale is a 23-item instrument with five subscales staff–student relationships, nurse manager commitment, patient relationships, interpersonal relationships, and student satisfaction These factors have strong substantive face validity and construct validity, as determined by confirmatory factor analysis Reliability coefficients range from high (0 85) to marginal (0 63) The CLE scale provides the educator with a valid and reliable instrument to evaluate affectively relevant factors in the CLE, direct resources to areas where improvement may be required, and nurture those areas functioning well It will assist in the application of resources in a cost-effective, efficient, productive manner, and will ensure that the clinical learning experience offers the nursing student the best possible learning outcomes

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Background - This study examined demographic profile, continuation rates and reasons for removal among Implanon® users accessing two family planning clinics in Queensland, Australia. Study Design - A retrospective chart audit of 976 women who attended for implant insertion over a 3-year period between May 2001 and May 2004. Results - Continuation rates showed that at 6 months after insertion, 94% of women continued, 74% continued at 1 year and 50% continued at 2 years. Metropolitan women were more likely than rural women to discontinue use because of dissatisfaction with bleeding patterns. Cox regression analysis showed that those attending the regional clinic experienced significantly shorter time to removal. Conclusions - Implanon® continuation rates and reasons for removal differ between clinics in metropolitan and rural locations. A cooling-off period did not affect the likelihood of continuation with Implanon®. Preinsertion counselling should emphasize potential changes in bleeding patterns.

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This paper explores the intentions and willingness of a sample of Australian consumers (N = 356) to use Complementary and Alternative Medicine (CAM). Participants considered using CAMs at least once in the next two months and rated the likelihood of certain consequences of CAM use, whether important others would approve, and if barriers would prevent them from using CAMs. People intending to use CAMs (high intenders) were more likely than those low on intention (low intenders) to endorse positive outcomes of CAM use and believe that important others would support their CAM use. High intenders were less likely than low intenders to believe that barriers would prevent use. Low intenders (n = 200) were also asked to consider their response to a free CAM trial. Those willing to accept a trial were more likely than those unwilling to believe that CAMs could improve health and less likely to believe that laziness would prevent use. These results identify important beliefs which may influence people’s decisions to use CAMs.

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Extended spectrum β-lactamases or ESBLs, which are derived from non-ESBL precursors by point mutation of β-lactamase genes (bla), are spreading rapidly all over the world and have caused considerable problems in the treatment of infections caused by bacteria which harbour them. The mechanism of this resistance is not fully understood and a better understanding of these mechanisms might significantly impact on choosing proper diagnostic and treatment strategies. Previous work on SHV β-lactamase gene, blaSHV, has shown that only Klebsiella pneumoniae strains which contain plasmid-borne blaSHV are able to mutate to phenotypically ESBL-positive strains and there was also evidence of an increase in blaSHV copy number. Therefore, it was hypothesised that although specific point mutation is essential for acquisition of ESBL activity, it is not yet enough, and blaSHV copy number amplification is also essential for an ESBL-positive phenotype, with homologous recombination being the likely mechanism of blaSHV copy number expansion. In this study, we investigated the mutation rate of non-ESBL expressing K. pneumoniae isolates to an ESBL-positive status by using the MSS-maximum likelihood method. Our data showed that blaSHV mutation rate of a non-ESBL expressing isolate is lower than the mutation rate of the other single base changes on the chromosome, even with a plasmid-borne blaSHV gene. On the other hand, mutation rate from a low MIC ESBL-positive (≤ 8 µg/mL for cefotaxime) to high MIC ESBL-positive (≥16 µg/mL for cefotaxime) is very high. This is because only gene copy number increase is needed which is probably mediated by homologous recombination that typically takes place at a much higher frequencies than point mutations. Using a subinhibitory concentration of novobiocin, as a homologous recombination inhibitor, revealed that this is the case.

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Citrus canker is a disease of citrus and closely related species, caused by the bacterium Xanthomonas citri subsp. citri. This disease, previously exotic to Australia, was detected on a single farm [infested premise-1, (IP1). IP is the terminology used in official biosecurity protocols to describe a locality at which an exotic plant pest has been confirmed or is presumed to exist. IP are numbered sequentially as they are detected] in Emerald, Queensland in July 2004. During the following 10 months the disease was subsequently detected on two other farms (IP2 and IP3) within the same area and studies indicated the disease first occurred on IP1 and spread to IP2 and IP3. The oldest, naturally infected plant tissue observed on any of these farms indicated the disease was present on IP1 for several months before detection and established on IP2 and IP3 during the second quarter (i.e. autumn) 2004. Transect studies on some IP1 blocks showed disease incidences ranged between 52 and 100% (trees infected). This contrasted to very low disease incidence, less than 4% of trees within a block, on IP2 and IP3. The mechanisms proposed for disease spread within blocks include weather-assisted dispersal of the bacterium (e.g. wind-driven rain) and movement of contaminated farm equipment, in particular by pivot irrigator towers via mechanical damage in combination with abundant water. Spread between blocks on IP2 was attributed to movement of contaminated farm equipment and/or people. Epidemiology results suggest: (i) successive surveillance rounds increase the likelihood of disease detection; (ii) surveillance sensitivity is affected by tree size; and (iii) individual destruction zones (for the purpose of eradication) could be determined using disease incidence and severity data rather than a predefined set area.

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This article describes the theoretical underpinning and development of a measurement instrument that provides teachers with a tool to observe the personal creativity characteristics of individual students. The instrument was developed by compiling a list of characteristics derived from the literature to be indicative of the personal characteristics of creative people. The list was then reduced by grouping like characteristics to 9 cognitive and dispositional traits that were considered appropriate for elementary students. The 9-item instrument was then administered in 24 classrooms to 520 Year 6 and Year 7 students. Factor analysis using maximum likelihood extraction with an oblimin rotation revealed a single factor with an eigenvalue greater than 1 and accounting for 63% of the variance. All 9 items on this factor loaded at .72 or greater. The results indicated that the Creativity Checklist has very high internal consistency and is a reliable measurement instrument (a = .93).

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To navigate successfully in a previously unexplored environment, a mobile robot must be able to estimate the spatial relationships of the objects of interest accurately. A Simultaneous Localization and Mapping (SLAM) sys- tem employs its sensors to build incrementally a map of its surroundings and to localize itself in the map simultaneously. The aim of this research project is to develop a SLAM system suitable for self propelled household lawnmowers. The proposed bearing-only SLAM system requires only an omnidirec- tional camera and some inexpensive landmarks. The main advantage of an omnidirectional camera is the panoramic view of all the landmarks in the scene. Placing landmarks in a lawn field to define the working domain is much easier and more flexible than installing the perimeter wire required by existing autonomous lawnmowers. The common approach of existing bearing-only SLAM methods relies on a motion model for predicting the robot’s pose and a sensor model for updating the pose. In the motion model, the error on the estimates of object positions is cumulated due mainly to the wheel slippage. Quantifying accu- rately the uncertainty of object positions is a fundamental requirement. In bearing-only SLAM, the Probability Density Function (PDF) of landmark position should be uniform along the observed bearing. Existing methods that approximate the PDF with a Gaussian estimation do not satisfy this uniformity requirement. This thesis introduces both geometric and proba- bilistic methods to address the above problems. The main novel contribu- tions of this thesis are: 1. A bearing-only SLAM method not requiring odometry. The proposed method relies solely on the sensor model (landmark bearings only) without relying on the motion model (odometry). The uncertainty of the estimated landmark positions depends on the vision error only, instead of the combination of both odometry and vision errors. 2. The transformation of the spatial uncertainty of objects. This thesis introduces a novel method for translating the spatial un- certainty of objects estimated from a moving frame attached to the robot into the global frame attached to the static landmarks in the environment. 3. The characterization of an improved PDF for representing landmark position in bearing-only SLAM. The proposed PDF is expressed in polar coordinates, and the marginal probability on range is constrained to be uniform. Compared to the PDF estimated from a mixture of Gaussians, the PDF developed here has far fewer parameters and can be easily adopted in a probabilistic framework, such as a particle filtering system. The main advantages of our proposed bearing-only SLAM system are its lower production cost and flexibility of use. The proposed system can be adopted in other domestic robots as well, such as vacuum cleaners or robotic toys when terrain is essentially 2D.

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Despite changes in surgical techniques, radiotherapy targeting and the apparent earlier detection of cancers, secondary lymphoedema is still a significant problem for about 20–30% of those who receive treatment for cancer, although the incidence and prevalence does seem to be falling. The figures above generally relate to detection of an enlarged limb or other area, but it seems that about 60% of all patients also suffer other problems with how the limb feels, what can or cannot be done with it and a range of social or psychological issues. Often these ‘subjective’ changes occur before the objective ones, such as a change in arm volume or circumference. For most of those treated for cancer lymphoedema does not develop immediately, and, while about 60–70% develop it in the first few years, some do not develop lymphoedema for up to 15 or 20 years. Those who will develop clinically manifest lymphoedema in the future are, for some time, in a latent or hidden phase of lymphoedema. There also seems to be some risk factors which are indicators for a higher likelihood of lymphoedema post treatment, including oedema at the surgical site, arm dominance, age, skin conditions, and body mass index (BMI).

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Young adults are at the greatest risk of experiences road trauma disproportionately to those in other age groups. While the influence of peers is commonly associated with motor vehicle crashes and injury few studies examine whether their influence can be positive. In particular friends may be able to actively intervene to reduce the likelihood of risky driving (e.g. speeding, drink driving or drug driving) and alcohol use. The aim of this paper is to conduct a systematic review on intervening in risky driving behaviour including the situations in which it is likely or unlikely to occur, factors associated with individuals who might or report having intervened and any evaluated programs that make use of such strategies. In addition a study was conducted with 247 first year university students (32% males) to examine whether young adults report engaging in protective behaviour with their peers in South-east Queensland. In particular, if they intervene if their friends are about to drive after drinking, drive after taking illicit drugs or when speeding. It examines any differences in reported likelihood of discouraging such illegal and dangerous behaviour (in the past 12 months prior to the survey). Findings showed that young adults (17-25 years) did indeed report protective behaviour in relation to friends’ drink driving, drug driving, speeding and binge drinking. Conclusions will be drawn regarding important considerations in developing positive strategies and advertising campaigns that encourage positive behaviours (e.g. ‘don’t let mates drink and drive’).

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Rural land prices, in developed, free trade real estate markets, are influenced not only by prevailing economic conditions but also physical factors such as climate, topography and soil type. In broad acre farming and grazing operations, both commodity price and yields determine farm income. Yields, in turn, are a function of climate, topography and soil type. The strength of a rural land market is influenced by the overall rural economy in a Country, State or region. These differences in rural land markets can also vary within smaller regions. It has been held that rural land, in relative safe production areas, is less effected by adverse economic and climatic factors than land in more marginal agricultural areas. This paper will analyse rural land sales in both traditional cropping areas and marginal cropping areas for the period 1975 to 1996. The analysis will determine the overall trend in rural land prices over the period, compare the average annual return between marginal and established farming areas and determine which economic and production factors have influenced this change. The impact of this analysis will also be discussed in relation to rural land appraisal.

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Since at least the 1960s, art has assumed a breadth of form and medium as diverse as social reality itself. Where once it was marginal and transgressive for artists to work across a spectrum of media, today it is common practice. In this ‘post-medium’ age, fidelity to a specific branch of media is a matter of preference, rather than a code of practice policed by gallerists, curators and critics. Despite the openness of contemporary art practice, the teaching of art at most universities remains steadfastly discipline-based. Discipline-based art teaching, while offering the promise of focussed ‘mastery’ of a particular set of technical skills and theoretical concerns, does so at the expense of a deeper and more complex understanding of the possibilities of creative experimentation in the artist’s studio. By maintaining an hermetic approach to medium, it does not prepare students sufficiently for the reality of art making in the twenty-first century. In fact, by pretending that there is a select range of techniques fundamental to the artist’s trade, discipline-based teaching can often appear to be more engaged with the notion of skills preservation than purposeful art training. If art schools are to survive and prosper in an increasingly vocationally-oriented university environment, they need to fully synthesise the professional reality of contemporary art practice into their approach to teaching and learning. This paper discusses the way in which the ‘open’ studio approach to visual art study at QUT endeavours to incorporate the diversity and complexity of contemporary art while preserving the sense of collective purpose that discipline-based teaching fosters. By allowing students to independently develop their own art practices while also applying collaborative models of learning and assessment, the QUT studio program aims to equip students with a strong sense of self-reliance, a broad awareness and appreciation of contemporary art, and a deep understanding of studio-based experimentation unfettered by the boundaries of traditional media: all skills fundamental to the practice of contemporary art.

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Traffic congestion is an increasing problem with high costs in financial, social and personal terms. These costs include psychological and physiological stress, aggressivity and fatigue caused by lengthy delays, and increased likelihood of road crashes. Reliable and accurate traffic information is essential for the development of traffic control and management strategies. Traffic information is mostly gathered from in-road vehicle detectors such as induction loops. Traffic Message Chanel (TMC) service is popular service which wirelessly send traffic information to drivers. Traffic probes have been used in many cities to increase traffic information accuracy. A simulation to estimate the number of probe vehicles required to increase the accuracy of traffic information in Brisbane is proposed. A meso level traffic simulator has been developed to facilitate the identification of the optimal number of probe vehicles required to achieve an acceptable level of traffic reporting accuracy. Our approach to determine the optimal number of probe vehicles required to meet quality of service requirements, is to simulate runs with varying numbers of traffic probes. The simulated traffic represents Brisbane’s typical morning traffic. The road maps used in simulation are Brisbane’s TMC maps complete with speed limits and traffic lights. Experimental results show that that the optimal number of probe vehicles required for providing a useful supplement to TMC (induction loop) data lies between 0.5% and 2.5% of vehicles on the road. With less probes than 0.25%, little additional information is provided, while for more probes than 5%, there is only a negligible affect on accuracy for increasingly many probes on the road. Our findings are consistent with on-going research work on traffic probes, and show the effectiveness of using probe vehicles to supplement induction loops for accurate and timely traffic information.

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Surveillance networks are typically monitored by a few people, viewing several monitors displaying the camera feeds. It is then very difficult for a human operator to effectively detect events as they happen. Recently, computer vision research has begun to address ways to automatically process some of this data, to assist human operators. Object tracking, event recognition, crowd analysis and human identification at a distance are being pursued as a means to aid human operators and improve the security of areas such as transport hubs. The task of object tracking is key to the effective use of more advanced technologies. To recognize an event people and objects must be tracked. Tracking also enhances the performance of tasks such as crowd analysis or human identification. Before an object can be tracked, it must be detected. Motion segmentation techniques, widely employed in tracking systems, produce a binary image in which objects can be located. However, these techniques are prone to errors caused by shadows and lighting changes. Detection routines often fail, either due to erroneous motion caused by noise and lighting effects, or due to the detection routines being unable to split occluded regions into their component objects. Particle filters can be used as a self contained tracking system, and make it unnecessary for the task of detection to be carried out separately except for an initial (often manual) detection to initialise the filter. Particle filters use one or more extracted features to evaluate the likelihood of an object existing at a given point each frame. Such systems however do not easily allow for multiple objects to be tracked robustly, and do not explicitly maintain the identity of tracked objects. This dissertation investigates improvements to the performance of object tracking algorithms through improved motion segmentation and the use of a particle filter. A novel hybrid motion segmentation / optical flow algorithm, capable of simultaneously extracting multiple layers of foreground and optical flow in surveillance video frames is proposed. The algorithm is shown to perform well in the presence of adverse lighting conditions, and the optical flow is capable of extracting a moving object. The proposed algorithm is integrated within a tracking system and evaluated using the ETISEO (Evaluation du Traitement et de lInterpretation de Sequences vidEO - Evaluation for video understanding) database, and significant improvement in detection and tracking performance is demonstrated when compared to a baseline system. A Scalable Condensation Filter (SCF), a particle filter designed to work within an existing tracking system, is also developed. The creation and deletion of modes and maintenance of identity is handled by the underlying tracking system; and the tracking system is able to benefit from the improved performance in uncertain conditions arising from occlusion and noise provided by a particle filter. The system is evaluated using the ETISEO database. The dissertation then investigates fusion schemes for multi-spectral tracking systems. Four fusion schemes for combining a thermal and visual colour modality are evaluated using the OTCBVS (Object Tracking and Classification in and Beyond the Visible Spectrum) database. It is shown that a middle fusion scheme yields the best results and demonstrates a significant improvement in performance when compared to a system using either mode individually. Findings from the thesis contribute to improve the performance of semi-automated video processing and therefore improve security in areas under surveillance.

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Tissue damage resulting from the extracellular production of HOCl (hypochlorous acid) by the MPO (myeloperoxidase)-hydrogen peroxide-chloride system of activated phagocytes is implicated as a key event in the progression of a number of human inflammatory diseases. Consequently, there is considerable interest in the development of therapeutically useful MPO inhibitors. Nitroxides are well established antioxidant compounds of low toxicity that can attenuate oxidative damage in animal models of inflammatory disease. They are believed to exert protective effects principally by acting as superoxide dismutase mimetics or radical scavengers. However, we show here that nitroxides can also potently inhibit MPO-mediated HOCl production, with the nitroxide 4-aminoTEMPO inhibiting HOCl production by MPO and by neutrophils with IC50 values of approx. 1 and 6 μM respectively. Structure–activity relationships were determined for a range of aliphatic and aromatic nitroxides, and inhibition of oxidative damage to two biologically-important protein targets (albumin and perlecan) are demonstrated. Inhibition was shown to involve one-electron oxidation of the nitroxides by the compound I form of MPO and accumulation of compound II. Haem destruction was also observed with some nitroxides. Inhibition of neutrophil HOCl production by nitroxides was antagonized by neutrophil-derived superoxide, with this attributed to superoxide-mediated reduction of compound II. This effect was marginal with 4-aminoTEMPO, probably due to the efficient superoxide dismutase-mimetic activity of this nitroxide. Overall, these data indicate that nitroxides have considerable promise as therapeutic agents for the inhibition of MPO-mediated damage in inflammatory diseases.