96 resultados para automated instruments

em Deakin Research Online - Australia


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We present a fully automated DNA purification module comprised of a micro-fabricated chip and sequential injection analysis system that is designed for use within autonomous instruments that continuously monitor the environment for the presence of biological threat agents. The chip has an elliptical flow channel containing a bed (3.5 × 3.5 mm) of silica-coated pillars with height, width and center-to-center spacing of 200, 15, and 30 µm, respectively, which provides a relatively large surface area (ca. 3 cm2) for DNA capture in the presence of chaotropic agents. We have characterized the effect of various fluidic parameters on extraction performance, including sample input volume, capture flow rate, and elution volume. The flow-through design made the pillar chip completely reusable; carryover was eliminated by flushing lines with sodium hypochlorite and deionized water between assays. A mass balance was conducted to determine the fate of input DNA not recovered in the eluent. The device was capable of purifying and recovering Bacillus anthracis genomic DNA (input masses from 0.32 to 320 pg) from spiked environmental aerosol samples, for subsequent analysis using polymerase chain reaction-based assays.

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It is a privilege to have the opportunity to respond to the comments on my monograph1 provided by Mark Gergen, Glenn May, and Gordon Longhouse. Their comments, which are inevitably coloured by their very different perspectives, reflect the considerable expertise that each one of them has in the area of the income taxation of financial instruments. Indeed, it is with some hesitation that I offer a response in defence of various portions of the analysis presented in my monograph in support of some pretty modest proposals in this extremely difficult area of income tax law. Although I spent considerable time exploring some necessary first principles and their implications for the design of a system for the income taxation of financial instruments, I made several concessions to certain practical constraints that led me to support, in some measure, the status quo reflected in certain of the existing literature, as well as the legislation in a select group of countries. On the assumption that many readers may be unfamiliar with the monograph, I propose to respond by outlining much of my analysis in the monograph and the proposals that are the logical outcome. Throughout the outline, I will highlight and respond to what I see as the important points of difference emphasized by Gergen, May, and Longhouse.

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The quality of life of caregivers of patients with cancer is an important construct given the substantial impact of caring on the physical, psychological, social, and financial well-being of caregivers. Moreover, caring for patients with cancer also affects family functioning and places burdens on caregivers. The reliability and validity of instruments used to assess the quality of life of caregivers of patients with cancer were reviewed to aid in the selection of the most appropriate measures For research and practice. MEDLINE (1980-2000) and c/NAHL (1982-2000) searches located relevant quality of life instruments using the keywords "cancer and quality of Iife" and "caregiver or spouse or partner." The search identified the following instruments: the Caregiver Quality of life Index-Cancer Scale, the 'Caregiver Quality of Life Index, the Quality of Life Tool, and the Quality of life Index-Cancer Version. Quality of life instruments developed specifically to measure the quality of life of caregivers of patients with cancer had the best psychometric properties. The Caregiver Quality of Life Index-Cancer Scale, in particular, met or exceeded minimum psychometric criteria for reliability and validity. The development of reliable and valid caregiver quality of life measures is an important factor in developing interventions to enhance quality of life of caregivers of patients with cancer.

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With an increasing number of paediatric quality of life (QOL) instruments being developed, it is becoming difficult for researchers and clinicians to select the most appropriate instrument. Reviews of QOL instruments tend to report only basic properties of the instruments such as domains and psychometric properties. This paper seeks to appraise critically the conceptual underpinnings of paediatric QOL instruments. A systematic review was conducted to identify QOL instruments for children aged 0 to 12 years, and to examine and compare their conceptual frameworks, definitions employed, and structure. Both generic and condition-specific measures were reviewed. Fourteen generic and 25 condition-specific QOL instruments were identified. Eleven types of definition of QOL and health-related QOL and three theories of QOL were identified. QOL was measured by a variety of domains including emotional, social and physical health, and well-being. Items commonly assessed difficulties, or intensity/frequency of feelings/symptoms, in contrast to positive aspects of life and happiness. The findings highlight the diversity that is apparent in the conceptualization of paediatric QOL and draw attention to the lack of empirical evidence for many of the fundamental assumptions. The impact of the conceptual underpinnings of the instruments on the resulting QOL scores is discussed.

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In a recent issue of this journal Nguyen and Faff (2002) reported on an empirical exploration of the motives behind the aggregate use of financial derivatives by Australian companies. Employing the same sample of firms, the current paper extends their analysis to investigate similar issues, this time focussing separately on foreign currency and interest rate derivatives. At a specific level, our results reveal the following. A firm is more likely to use foreign currency derivatives if it is large and has more debt in its capital structure. Interest rate derivatives, on the other hand, are more likely to be used if a firm is larger, more levered, more liquid and pays higher dividends. These results are consistent with existing hedging theories. Market to book value (proxying growth opportunities), however, portrays an inconsistent relationship with the likelihood of interest rate derivative usage. When it comes to the extent of usage, a firm uses foreign currency derivatives more extensively if it is smaller, pays higher dividends and has more debt. Similarly, interest rate derivatives are used more extensively to address a high level of debt and a high dividend payout policy. At a general level, the current study confirms the core finding of Nguyen and Faff (2002), namely, that Australian companies use derivatives with a view to value maximisation.

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This paper examines methods of point wise construction of aggregation operators via optimal interpolation. It is shown that several types of application-specific requirements lead to interpolatory type constraints on the aggregation function. These constraints are translated into global optimization problems, which are the focus of this paper. We present several methods of reduction of the number of variables, and formulate suitable numerical algorithms based on Lipschitz optimization.

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A high-performance liquid chromatography (HPLC) method for the determination of urea that incorporates automated derivatisation with xanthydrol (9H-xanthen-9-ol) is described. Unlike the classic xanthydrol approach for the determination of urea, which involves the precipitation of dixanthylurea (N,N′-di-9H-xanthen-9-ylurea), the derivatisation procedure employed in this method produces N-9H-xanthen-9-ylurea, which remains in solution and can be quantified using fluorescence detection (λex = 213 nm; λem = 308 nm) after chromatographic separation from interferences. The limit of detection for urea was 5 × 10−8 M (0.003 mg L−1). This method was applied to the determination of urea in human and animal urine and in wine.

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A new robotic grinding process has been developed for a low-powered robot system using a spring balancer as a suspension system. To manipulate a robot-arm in the vertical plane, a large actuator torque is required due to the tool weight and enormous gravity effect. But the actuators of the robot system always exhibit a limited torque capacity. This paper presents a cheap and available system for precise grinding tasks by a low-powered robot system using a suspension system. For grinding operations, to achieve position and force-tracking simultaneously, this paper presents an algorithm of the hybrid position/force-tracking scheme with respect to the dynamic behavior of a spring balancer. Material Removal Rate (MRR) is developed for materials SS400 and SUS304. Simulations and experiments have been carried out to demonstrate the feasibility of the proposed system.


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Objectives: To assess the value of computerised decision support in the management of chronic respiratory disease by comparing agreement between three respiratory specialists, general practitioners (care coordinators), and decision support software.
Methods: Care guidelines for two chronic obstructive pulmonary disease projects of the SA HealthPlus Coordinated Care Trial were formulated. Decision support software, Care Plan On-Line (CPOL), was created to represent the intent of these guidelines via automated attention flags to appear in patients' electronic medical records. For a random sample of 20 patients with care plans, decisions about the use of nine additional services (eg,.smoking cessation, pneumococcal vaccination) were compared between the respiratory specialists, the patients' GPs and the CPOL attention flags.
Results: Agreement among the specialists was at the lower end of moderate (intraclass correlation coefficient [ICC], 0.48; 95% CI, 0.39-0.56), with a 20% rate of contradictory decisions. Agreement with recommendations of specialists was moderate to poor for GPs (le, 0.49; 95% CI, 0.33-0.66) and moderate to good for CPOL (K, 0.72; 95% CI, 0.55-0.90). CPOL agreement with GPs was moderate to poor (le, 0.41; 95% CI, 0.24-0.58). GPs were less likely than specialists or CPOL to decide in favour of an additional service (P< 0.001). CPOL was 87% accurate as an indicator of specialist decisions. It gave a 16% false-positive rate according to specialist decisions, and flagged 61% of decisions where GPs said No and specialists said Yes.
Conclusions: Automated decision support may provide GPs with improved access to the intent of guidelines; however, further investigation is required.

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Objective To describe the diagnostic performance of SolarScan (Polartechnics Ltd, Sydney, Australia), an automated instrument for the diagnosis of primary melanoma.

Design Images from a data set of 2430 lesions (382 were melanomas; median Breslow thickness, 0.36 mm) were divided into a training set and an independent test set at a ratio of approximately 2:1. A diagnostic algorithm (absolute diagnosis of melanoma vs benign lesion and estimated probability of melanoma) was developed and its performance described on the test set. High-quality clinical and dermoscopy images with a detailed patient history for 78 lesions (13 of which were melanomas) from the test set were given to various clinicians to compare their diagnostic accuracy with that of SolarScan.

Setting Seven specialist referral centers and 2 general practice skin cancer clinics from 3 continents. Comparison between clinician diagnosis and SolarScan diagnosis was by 3 dermoscopy experts, 4 dermatologists, 3 trainee dermatologists, and 3 general practitioners.

Patients Images of the melanocytic lesions were obtained from patients who required either excision or digital monitoring to exclude malignancy.

Main Outcome Measures Sensitivity, specificity, the area under the receiver operator characteristic curve, median probability for the diagnosis of melanoma, a direct comparison of SolarScan with diagnoses performed by humans, and interinstrument and intrainstrument reproducibility.

Results The melanocytic-only diagnostic model was highly reproducible in the test set and gave a sensitivity of 91% (95% confidence interval [CI], 86%-96%) and specificity of 68% (95% CI, 64%-72%) for melanoma. SolarScan had comparable or superior sensitivity and specificity (85% vs 65%) compared with those of experts (90% vs 59%), dermatologists (81% vs 60%), trainees (85% vs 36%; P =.06), and general practitioners (62% vs 63%). The intraclass correlation coefficient of intrainstrument repeatability was 0.86 (95% CI, 0.83-0.88), indicating an excellent repeatability. There was no significant interinstrument variation (P = .80).

Conclusions SolarScan is a robust diagnostic instrument for pigmented or partially pigmented melanocytic lesions of the skin. Preliminary data suggest that its performance is comparable or superior to that of a range of clinician groups. However, these findings should be confirmed in a formal clinical trial.

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Latest information, developments and statistics, with website addresses provided to allow students to access up to the minute, real-world data. Real-world examples throughout the text help students relate theory to pracical situations.