481 resultados para Frequency up-conversion
Resumo:
Thirty workers who had been exposed to combustion products for several years due to testing of flame retarding qualities of building materials and 30 controls from the same facility were investigated. Concentrations found in samples taken from different places of the facility were up to 14,660 μg/kg for polybrominated dibenzofurans and up to 67.1 μg/kg for polychlorinated dibenzodioxins (PCDDs) and dibenzofurans (PCDFs). Physical examination, routine laboratory parameters, and blood fat concentrations of PCDDs and PCDFs revealed normal findings. Neurotoxic symptoms showed a weak tendency of overrepresentation among the exposed workers. The frequency of neurobehavioural symptoms increased significantly with trait anxiety independent of exposure to combustion products. (C) 2000 Elsevier Science Ltd.
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Background: Nausea can be a debilitating symptom for patients with a life-limiting illness. While addressing reversible components, nonpharmacological strategies and antiemetics are the main therapeutic option. The choice of medication, dose, and route of administration remain highly variable. Objective: The aim of this study was to codify the current clinical approaches and quantify any variation found nationally. Methods: A cross-sectional study utilizing a survey of palliative medicine clinicians examined prescribing preferences for nausea using a clinical vignette. Respondent characteristics, the use of nonpharmacological interventions, first- and second-line antiemetic choices, commencing and maximal dose, and time to review were collected. Results: Responding clinicians were predominantly working in palliative medicine across a range of settings with a 49% response rate (105/213). The main nonpharmacological recommendation was “small, frequent snacks.” Metoclopramide was the predominant first-line agent (69%), followed by haloperidol (26%), while second-line haloperidol was the predominant agent (47%), with wide variation in other nominated agents. Respondents favoring metoclopramide as first-line tended to use haloperidol second-line (65%), but not vice versa. Maximal doses for an individual antiemetic varied up to tenfold. Conclusion: For nausea, a commonly encountered symptom in palliative care, clinicians' favored metoclopramide and haloperidol; however, after these choices, there was large variation in antiemetic selection. While most clinicians recommended modifying meal size and frequency, use of other nonpharmacological therapies was limited.
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Urban areas are growing unsustainably around the world; however, the growth patterns and their associated drivers vary between contexts. As a result, research has highlighted the need to adopt case study based approaches to stimulate the development of new theoretic understandings. Using land-cover data sets derived from Landsat images (30 m × 30 m), this research identifies both patterns and drivers of urban growth in a period (1991-2001) when a number of policy acts were enacted aimed at fostering smart growth in Brisbane, Australia. A linear multiple regression model was estimated using the proportion of lands that were converted from non-built-up (1991) to built-up usage (2001) within a suburb as a dependent variable to identify significant drivers of land-cover changes. In addition, the hot spot analysis was conducted to identify spatial biases of land-cover changes, if any. Results show that the built-up areas increased by 1.34% every year. About 19.56% of the non-built-up lands in 1991 were converted into built-up lands in 2001. This conversion pattern was significantly biased in the northernmost and southernmost suburbs in the city. This is due to the fact that, as evident from the regression analysis, these suburbs experienced a higher rate of population growth, and had the availability of habitable green field sites in relatively flat lands. The above findings suggest that the policy interventions undertaken between the periods were not as effective in promoting sustainable changes in the environment as they were aimed for.
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From Queensland’s inception as a self-governing colony in December 1859 the issue of labour relations has preoccupied governments and shaped the experiences of its working men and women. However, despite the often turbulent nature of labour relations in Queensland there has, prior to this book, been no attempt to provide an overview of the system as a whole. This important addition to Queensland’s sesquicentenary celebrations redresses this failure, looking at the diverse range of experiences that, together, made up a unique system of labour relations – including those of employers, women workers, indigenous workers, unions, the Queensland Industrial Relations Commission, labour law, industrial disputation, the workings of health and safety system and life in regional areas. It is argued that, overall, Queensland’s system of industrial regulation was central to its economic and social development. Despite past emphasis on the large-scale strikes that periodically raked the state this book finds that consensus normally prevailed.
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Objective Migraine is a highly disabling disease affecting a significant proportion of the Australian population. The Methylenetetrahydrofolate Reductase (MTHFR) C677T variant has been associated with increased levels of homocysteine and risk of migraine with aura (MA). Folic acid, Vitamin B6 and B12 supplementation has been previously shown to reduce increased levels of homocysteine and decrease migraine symptoms. However the influence of dietary folate intake on migraine has been unclear. The aim of the current study was to analyse the association of dietary folate intake in the form of dietary folate equivalent (DFE), folic acid (FA) and total food folate (TFF) on migraine frequency, severity and disability. Methods A cohort of 141 adult females of Caucasian descent with MA was genotyped for the MTHFRC677T variant using restriction enzyme digestion. Dietary folate information was collected from all participants and analysed using the “FoodWorks” 2009 package. Folate consumption was compared to migraine frequency, severity and disability using linear regression. Results A significant inverse relation was observed between DFE [R2= 0.201, P= 0.045, CI (-0.004, -0.001)] and FA [R2= 0.255, P= 0.036, 95% CI (-0.009, -0.002)] consumption and migraine frequency. It was also observed that in individuals with the CC genotype for the MTHFR C677T variant, migraine frequency was significantly linked to FA consumption [R2= 0.077, P= 0.029, CI (-0.009, -0.005)]. Conclusions The results from this study indicate that folate intake in the form of folic acid may influence migraine frequency in female MA sufferers.
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"For many Australians, January 10 last year is just a media memory — a vision of cars surfing down inner-city creeks in Toowoomba CBD and houses floating across farm paddocks in the Lockyer Valley. But for the people of the Lockyer Valley who were clinging to life, the terrifying visions of that day remain every time they close their eyes."
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To complement the existing treatment guidelines for all tumour types, ESMO organises consensus conferences to focus on specific issues in each type of tumour. The 2nd ESMO Consensus Conference on Lung Cancer was held on 11-12 May 2013 in Lugano. A total of 35 experts met to address several questions on non-small-cell lung cancer (NSCLC) in each of four areas: pathology and molecular biomarkers, first-line/second and further lines in advanced disease, earlystage disease and locally advanced disease. For each question, recommendations were made including reference to the grade of recommendation and level of evidence. This consensus paper focuses on early-stage disease. © The Author 2014. Published by Oxford University Press on behalf of the European Society for Medical Oncology. All rights reserved.
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This article responds to the invitation extended by Carney to engage in a dialogue on the topic of graduate legal research units. In his paper, Carney stated the approach of the Sydney course as being to teach theory rather than skills, to "pursue academic goals over skill competencies... ". The Faculty of Law at Queensland University of Technology introduced a postgraduate legal research unit in 1993 with different perspectives and purposes to the Sydney course, and given this experience, the opportunity for a discussion on aspects of such units including the theoretical versus practical approach to teaching cannot be ignored.
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Impaired driver alertness increases the likelihood of drivers’ making mistakes and reacting too late to unexpected events while driving. This is particularly a concern on monotonous roads, where a driver’s attention can decrease rapidly. While effective countermeasures do not currently exist, the development of in-vehicle sensors opens avenues for monitoring driving behavior in real-time. The aim of this study is to predict drivers’ level of alertness through surrogate measures collected from in-vehicle sensors. Electroencephalographic activity is used as a reference to evaluate alertness. Based on a sample of 25 drivers, data was collected in a driving simulator instrumented with an eye tracking system, a heart rate monitor and an electrodermal activity device. Various classification models were tested from linear regressions to Bayesians and data mining techniques. Results indicated that Neural Networks were the most efficient model in detecting lapses in alertness. Findings also show that reduced alertness can be predicted up to 5 minutes in advance with 90% accuracy, using surrogate measures such as time to line crossing, blink frequency and skin conductance level. Such a method could be used to warn drivers of their alertness level through the development of an in-vehicle device monitoring, in real-time, drivers' behavior on highways.
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Closed WS2 nanoboxes were formed by topotactic sulfidization of a WO3/WO3 center dot 1/3H(2)O intergrowth precursor. Automated diffraction tomography was used to elucidate the growth mechanism of these unconventional hollow structures. By partial conversion and structural analysis of the products, each of them representing a snapshot of the reaction at a given point in time, the overall reaction can be broken down into a cascade of individual steps and each of them identified with a basic mechanism. During the initial step of sulfidization WO3 center dot 1/3H(2)O transforms into hexagonal WO3 whose surface allows for the epitaxial induction of WS2. The initially formed platelets of WS2 exhibit a preferred orientation with respect to the nanorod surface. In the final step individual layers of WS2 coalesce to form closed shells. In essence, a cascade of several topotactic reactions leads to epitactic induction and formation of closed rectangular hollow boxes made up from hexagonal layers.
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The study investigated the adsorption and bioavailability characteristics of traffic generated metals common to urban land uses, in road deposited solids particles. To validate the outcomes derived from the analysis of field samples, adsorption and desorption experiments were undertaken. The analysis of field samples revealed that metals are selectively adsorbed to different charge sites on solids. Zinc, copper, lead and nickel are adsorbed preferentially to oxides of manganese, iron and aluminium. Lead is adsorbed to organic matter through chemisorption. Cadmium and chromium form weak bonding through cation exchange with most of the particle sizes. Adsorption and desorption experiments revealed that at high metal concentrations, chromium, copper and lead form relatively strong bonds with solids particles while zinc is adsorbed through cation exchange with high likelihood of being released back into solution. Outcomes from this study provide specific guidance for the removal of metals from stormwater based on solids removal.