277 resultados para Standardisation


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Quantitative measurement of the activity of photoactive films is an area of importance. The establishment of tests for standardisation of performance is important for efficient research but also a major milestone in achieving technology acceptance. In this paper, we compare three different techniques across a range of film samples from various sources. Furthermore, we demonstrate the potential of the dye-based approach as a quick and simple test. A series of photoactive film samples are compared for measured activity against each test. The test is shown to be capable of reproducible and quantitative activity results. The test has potential for use

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This paper explores the roles of science and market devices in the commodification of ‘nature’ and the configuration of flows of speculative capital. It focuses on mineral prospecting and the market for shares in ‘junior’ mining companies. In recent years these companies have expanded the reach of their exploration activities overseas, taking advantage of innovations in exploration methodologies and the liberalisation of fiscal and property regimes in ‘emerging’ mineral rich developing countries. Recent literature has explored how the reconfiguration of notions of ‘risk’ has structured the uneven distribution of rents. It is increasingly evident that neoliberal framing of environmental, political, social and economic risks has set in motion overflows that multinational mining capital had not bargained for (e.g. nationalisation, violence and political resistance). However, the role of ‘geological risk’ in animating flows of mining finance is often assumed as a ‘technical’ given. Yet geological knowledge claims, translated locally, designed to travel globally, assemble heterogeneous elements within distanciated regimes of metrology, valuation and commodity production. This paper explores how knowledge of nature is enrolled within systems of property relations, focusing on the genealogy of the knowledge practices that animate contemporary circuits of speculative mining finance. It argues that the financing of mineral prospecting mobilises pragmatic and situated forms of knowledge rather than actuarially driven calculations that promise predictability. A Canadian public enquiry struck in the wake of scandal associated with Bre-X’s prospecting activities in Indonesia is used to glean insights into the ways in which the construction of a system of public warrant to underpin financial speculation is predicated upon particular subjectivities and the outworking of everyday practices and struggles over ‘value’. Reflection on practical investments in processes of standardisation, rituals of verification and systems of accreditation reveal much about how the materiality of things shape the ways in which regional and global financial circuits are integrated, selectively transforming existing social relations and forms of knowledge production.

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OBJECTIVE: There is a widely recognised need to develop effective Alzheimer's disease (AD) biomarkers to aid the development of disease-modifying treatments, to facilitate early diagnosis and to improve clinical care. This overview aims to summarise the utility of key neuroimaging and cerebrospinal fluid (CSF) biomarkers for AD, before focusing on the latest efforts to identify informative blood biomarkers. DESIGN: A literature search was performed using PubMed up to September 2011 for reviews and primary research studies of neuroimaging (magnetic resonance imaging, magnetic resonance spectroscopy, positron emission tomography and amyloid imaging), CSF and blood-based (plasma, serum and platelet) biomarkers in AD and mild cognitive impairment. Citations within individual articles were examined to identify additional studies relevant to this review. RESULTS: Evidence of AD biomarker potential was available for imaging techniques reflecting amyloid burden and neurodegeneration. Several CSF measures are promising, including 42 amino acid ß-amyloid peptide (Aß(42) ); total tau (T-tau) protein, reflecting axonal damage; and phosphorylated tau (P-tau), reflecting neurofibrillary tangle pathology. Studies of plasma Aß have produced inferior diagnostic discrimination. Alternative plasma and platelet measures are described, which represent potential avenues for future research. CONCLUSIONS: Several imaging and CSF markers demonstrate utility in predicting AD progression and determining aetiology. These require standardisation before forming core elements of diagnostic criteria. The enormous potential available for identifying a minimally-invasive, easily-accessible blood measure as an effective AD biomarker currently remains unfulfilled. Copyright © 2012 John Wiley & Sons, Ltd.

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To overcome the weak evidence base coming from often poor and insufficient clinical research in older people, a minimum data set to achieve harmonisation is highly advisable. This will lead to uniform nomenclature and to the standardisation of the assessment tools. Our primary objective was to develop a Geriatric Minimum Data Set (GMDS) for clinical research.

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Chapter eleven on Mm-wave broadband wireless systems and enabling MMIC technologies, is contributed by Jian Zhang, Mury Thian, Guochi Huang, George Goussetis and Vincent F. Fusco, from Queen's University Belfast, UK. Millimeter wave bands provide large available bandwidths for high data rate wireless communication systems, which are envisaged to shift data throughput well in the GBps range. This capability has over past few years driven rapid developments in the technology underpinning broadband wireless systems as well as in the standardisation activity from various non-governmental consortia and the band allocation from spectrum regulators globally. This chapter provides an overview of the recent developments on V-band broadband wireless systems with the emphasis placed on enabling MMIC technologies. An overview of the key applications and available standards is presented. System-level architectures for broadband wireless applications are being reviewed. Examples of analysis, design and testing on MMIC components in SiGe BiCMOS are presented and the outlook of the technology is discussed.

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The full extent to which inherited disorders occur in different breeds of domestic horse (Equus caballus) has not been previously been investigated. A systematic search was carried out to review scientific literature on inherited disorders in domestic horse breeds and examine patterns in potentially inherited disorders. A two-part search was conducted: (i) electronic bibliographic databases for published studies; and (ii) existing online databases of inherited disorders in animals. A total of 230 papers were identified, discussing 102 inherited disorders in the horse. Few cases (17) were found in which disorders were reported to have a direct link to a conformational or phenotypic trait. Forty-nine breeds of domestic horse were described as being predisposed to one or more inherited disorders, but such predispositions did not distinguish between genetic or environmental causes. There were few patterns in the number of disorders to which breeds were reportedly predisposed or in the extent to which disorders were researched. The structure and grouping of disorders presented here could assist with standardisation in the terminology used for describing inherited disorders. © 2012 Universities Federation for Animal Welfare The Old School.

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Standardized patients (SPs) are often asked to award global scores on the humanistic aspects of a candidate’s performance in an OSCE. However, little is known about the process by which SPs arrive at their mark.
Five focus groups of SPs, using a convenience sample, were used to collect data until saturation. Thematic analysis was carried out independently by three researchers using a grounded theory approach.

Four major themes contributed to their decision-making process: environment, relationships within the exam, preparedness for the task and expectations of the student’s performance. Environmental factors included the station itself, the rating scale and examiner fatigue. Relationship factors included first impressions, the sense of purpose derived from examining and a tendency to mirror the examiner’s reaction. Factors relating to preparedness for task involved experience as an SP and technical aspects, such as the need for calibration. Lastly, expectations of performance were related to preconceptions about what makes a ‘good’ student, including their level of studies, appearance and technical performance.

In assessing students, SPs drew on their wider attitudes and experiences. SPs did not limit their assessment to humanistic traits but often included technical performance. Thus, SPs to some extent assessed a similar construct to examiners and this may help to explain the increased reliability associated with using SP scores. SP global scores are a useful adjunct but the process by which SPs award marks is complex and provides a challenge for training and standardisation.

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Purpose: In randomised clinical trials (RCTs) the selection of appropriate outcomes is crucial to the assessment of whether one intervention is better than another. The purpose of this review is to identify different clinical outcomes reported in glaucoma trials.

Methods We conducted a systematic review of glaucoma RCTs. A sample or selection of glaucoma trials were included bounded by a time frame (between 2006 and March 2012). Only studies in English language were considered. All clinical measured and reported outcomes were included. The possible variations of clinical outcomes were defined prior to data analysis. Information on reported clinical outcomes was tabulated and analysed using descriptive statistics. Other data recorded included type of intervention and glaucoma, duration of the study, defined primary outcomes, and outcomes used for sample size calculation, if nominated.

Results The search strategy identified 4323 potentially relevant abstracts. There were 315 publications retrieved, of which 233 RCTs were included. A total of 967 clinical measures were reported. There were large variations in the definitions used to describe different outcomes and their measures. Intraocular pressure was the most commonly reported outcome (used in 201 RCTs, 86%) with a total of 422 measures (44%). Safety outcomes were commonly reported in 145 RCTs (62%) whereas visual field outcomes were used in 38 RCTs (16%).

Conclusions There is a large variation in the reporting of clinical outcomes in glaucoma RCTs. This lack of standardisation may impair the ability to evaluate the evidence of glaucoma interventions.

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The ECFS-CTN Standardisation Committee has undertaken this review of lung clearance index as part of the group's work on evaluation of clinical endpoints with regard to their use in multicentre clinical trials in CF. The aims were 1) to review the literature on reliability, validity and responsiveness of LCI in patients with CF, 2) to gain consensus of the group on feasibility of LCI and 3) to gain consensus on answers to key questions regarding the promotion of LCI to surrogate endpoint status. It was concluded that LCI has an attractive feasibility and clinimetric properties profile and is particularly indicated for multicentre trials in young children with CF and patients with early or mild CF lung disease. This is the first article to collate the literature in this manner and support the use of LCI in clinical trials in CF.

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Background and purpose
The dominant psychometric discourse of OSCEs may lead to unexpected problems, such as a checklist-based student performance1 which under emphasises the clinical relationship with student and standardised patient (SP). Such encounters can be dehumanising for SPs2 and have implications for what students learn about relational skills through the assessment process. In this study we explore medical students’ experiences of undertaking OSCEs using a phenomenological frame.
Methodology
Interpretative phenomenological analysis is a form of qualitative methodology which has strong resonance with existentialism and focuses on the lived experience without significant reference to external political or discursive
forces.
Six 4th year undergraduate medical students from Queen’s University Belfast were recruited in December 2013. Maximum variation sampling was used. Students were interviewed by a researcher in the week prior to the
OSCE and then again in the week following the OSCE in Jan 2014. Interviews were minimally structured in order to be open to respondents, rather than adhering to a fixed topic guide, but focussed on participants’ experiences, thoughts and feelings about taking part in OSCEs. Interviews were audio-recorded and
transcribed. Students were also asked to complete a short diary entry in the days prior to the OSCEs and another immediately following. Diary entries were written, emailed or audio-recorded at student’s preference.
Results
Transcripts are currently being analysed by interpretative phenomenological analysis. Preliminary analysis has demonstrated the significance of students’ relationships within the OSCE triad (student, SP and examiner); the effect of the immediate examination environment; realism versus roleplay; students’ perceptions of the purpose of assessment; and coping mechanisms.
Full results will be available by the time of the conference.
Conclusion and Discussion
Understanding the student experience in OSCEs is a crucial step in understanding the complex construction of relationships within the OSCE triad. The focus in OSCEs is typically on standardisation and reliability, but in exploring social interactions we may refocus attention on their inherent potential for learning and effects on both students and patients.
References
1. Hodges B. Medical education and the maintenance of incompetence. Med Teach 2006;28(8):690-6
2. Johnston JL, Lundy G, McCullough M, Gormley GJ. The view from over there: reframing the OSCE through the experience of standardised patient
raters. Med Educ 2013;47(9):899-909

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Background: In clinical trials the selection of appropriate outcomes is crucial to the assessment of whether one intervention is better than another. Glaucoma is a chronic eye disease and the leading cause of irreversible blindness in the world. A variety of outcomes has been used and reported in glaucoma RCTs.

Objectives: The purpose of this review is to identify different clinical outcome measures used in glaucoma RCTs between January 2006 and March 2012.

Methods: A systematic review was conducted using standard methodology. We searched for RCTs in glaucoma published in English with no restrictions on the population type or size, or applied interventions. All clinical outcomes were included. Patient-reported, pharmacokinetic and economic outcomes were excluded.

Results: The search strategy identified 4288 potentially relevant abstracts. There were 315 publications retrieved, of which 233 RCTs were included. A total of 967 clinical measures were reported. There were large variations in the definitions used to describe different outcomes and their measures. Intraocular pressure (IOP) was the most commonly reported outcome (used in 201 RCTs, 86%) with a total of 422 measures (44%). Amongst the IOPrelated measures, the most commonly used was mean IOP (n=143, 15% of all measures). Safety outcomes were commonly reported, in 145 RCTs (62%) whereas visual field outcomes were utilized in 38 RCTs (16%).

Conclusions: There is a large variability in clinical outcomes used for glaucoma RCTs and in the way each outcome is reported. This lack of standardisation may impair the ability to evaluate the evidence of glaucoma interventions.

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There have been important recent developments in law, research, policy and practice relating to supporting people with decision-making impairments, in particular when a person’s wishes and preferences are unclear or inaccessible. A driver in this respect is the United Nations Convention on the Rights of Persons with Disabilities (CRPD); the implications of the CRPD for policy and professional practices are currently debated. This article reviews and compares four legal frameworks for supported and substitute decision-making for people whose decision-making ability is impaired. In particular, it explores how these frameworks may apply to people with mental health problems. The four jurisdictions are: Ontario, Canada; Victoria, Australia; England and Wales, United Kingdom (UK); and Northern Ireland, UK. Comparisons and contrasts are made in the key areas of: the legal framework for supported and substitute decision-making; the criteria for intervention; the assessment process; the safeguards; and issues in practice. Thus Ontario has developed a relatively comprehensive, progressive and influential legal framework over the past thirty years but there remain concerns about the standardisation of decision-making ability assessments and how the laws work together. In Australia, the Victorian Law Reform Commission (2012) has recommended that the six different types of substitute decision-making under the three laws in that jurisdiction, need to be simplified, and integrated into a spectrum that includes supported decision-making. In England and Wales the Mental Capacity Act 2005 has a complex interface with mental health law. In Northern Ireland it is proposed to introduce a new Mental Capacity (Health, Welfare and Finance) Bill that will provide a unified structure for all substitute decision-making. The discussion will consider the key strengths and limitations of the approaches in each jurisdiction and identify possible ways that further progress can be made in law, policy and practice.

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PurposeThe selection of suitable outcomes and sample size calculation are critical factors in the design of a randomised controlled trial (RCT). The goal of this study was to identify the range of outcomes and information on sample size calculation in RCTs on geographic atrophy (GA).MethodsWe carried out a systematic review of age-related macular degeneration (AMD) RCTs. We searched MEDLINE, EMBASE, Scopus, Cochrane Library, www.controlled-trials.com, and www.ClinicalTrials.gov. Two independent reviewers screened records. One reviewer collected data and the second reviewer appraised 10% of collected data. We scanned references lists of selected papers to include other relevant RCTs.ResultsLiterature and registry search identified 3816 abstracts of journal articles and 493 records from trial registries. From a total of 177 RCTs on all types of AMD, 23 RCTs on GA were included. Eighty-one clinical outcomes were identified. Visual acuity (VA) was the most frequently used outcome, presented in 18 out of 23 RCTs and followed by the measures of lesion area. For sample size analysis, 8 GA RCTs were included. None of them provided sufficient Information on sample size calculations.ConclusionsThis systematic review illustrates a lack of standardisation in terms of outcome reporting in GA trials and issues regarding sample size calculation. These limitations significantly hamper attempts to compare outcomes across studies and also perform meta-analyses.

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This paper describes the methodology, results and limitations of the 2013 International Diabetes Federation (IDF) Atlas (6th edition) estimates of the worldwide numbers of prevalent cases of type 1 diabetes in children (<15 years). The majority of relevant information in the published literature is in the form of incidence rates derived from registers of newly diagnosed cases. Studies were graded on quality criteria and, if no information was available in the published literature, extrapolation was used to assign a country the rate from an adjacent country with similar characteristics. Prevalence rates were then derived from these incidence rates and applied to United Nations 2012 Revision population estimates for 2013 for each country to obtain estimates of the number of prevalent cases. Data availability was highest for the countries in Europe (76%) and lowest for the countries in sub-Saharan Africa (8%). The prevalence estimates indicate that there are almost 500,000 children aged under 15 years with type 1 diabetes worldwide, the largest numbers being in Europe (129,000) and North America (108,700). Countries with the highest estimated numbers of new cases annually were the United States (13,000), India (10,900) and Brazil (5000). Compared with the prevalence estimates made in previous editions of the IDF Diabetes Atlas, the numbers have increased in most of the IDF Regions, often reflecting the incidence rate increases that have been well-documented in many countries. Monogenic diabetes is increasingly being recognised among those with clinical features of type 1 or type 2 diabetes as genetic studies become available, but population-based data on incidence and prevalence show wide variation due to lack of standardisation in the studies. Similarly, studies on type 2 diabetes in childhood suggest increased incidence and prevalence in many countries, especially in Indigenous peoples and ethnic minorities, but detailed population-based studies remain limited.

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Dissertação de Mestrado submetida ao Instituto Superior de Contabilidade e Administração do Porto para a obtenção do grau de Mestre em Auditoria Trabalho efetuado sob a orientação do Mestre Carlos Martins