302 research outputs found
Colour Relations in Form
Get PDFThe orthodox monadic determination thesis holds that we represent colour relations by virtue of representing colours. Against this orthodoxy, I argue that it is possible to represent colour relations without representing any colours. I present a model of iconic perceptual content that allows for such primitive relational colour representation, and provide four empirical arguments in its support. I close by surveying alternative views of the relationship between monadic and relational colour representation
Virtual Prototyping, Identification and Control of a Twin Rotor with 3DOF
Full text linkThis paper presents a methodology for identification of the physical characteristics, generation of the mathematical model through virtual prototyping and control of the didactic plant of a twin rotor. In the identification of the physical characteristics, the centers of mass and moments of inertia of the twin rotor parts were identified separately, by means of an easel designed for such task. Still in the identification of the physical characteristics, the equation that relates the applied voltage in the direct current motor with the thrust force produced by the propellers was obtained. The mathematical model of the twin rotor was obtained by means of the identification of the physical characteristics allied to the virtual prototyping with the aid of ADAMS and SolidWorks software. The implemented control system uses state feedback and complete eigenstructure assignment. The ease and usefulness of the proposed methodology was presented through the plant instrumentation, simulation and control in MATLAB/Simulink environment
Quality of life assessment of cabozantinib in patients with advanced hepatocellular carcinoma in the CELESTIAL trial
Get PDFBACKGROUND: The CELESTIAL trial (NCT01908426) demonstrated overall survival benefit for cabozantinib versus placebo in patients with advanced hepatocellular carcinoma (aHCC) who had received prior sorafenib treatment. This analysis of CELESTIAL compared the impact of cabozantinib versus placebo on health-related quality of life (HRQoL).
MATERIALS AND METHODS: Health status was assessed using the EuroQol five-dimension five-level (EQ-5D-5L) questionnaire over the 800-day follow-up period. EQ-5D-5L health states were mapped to health utility scores using reference values for the UK population. Quality-adjusted life years (QALYs) were calculated for each treatment group as the area under the curve for the plot of health utility score over time. The between-treatment group difference in restricted mean QALYs was calculated by generalized linear models and adjusted for baseline differences. A difference of 0.08 in health utility score (or in QALY) was deemed a minimally important difference and to be clinically significant.
RESULTS: At week 5, the difference in mean health utility score between cabozantinib and placebo was -0.097 (95% confidence interval [95% CI]: -0.126, -0.067; pĀ ā¤Ā 0.001). Between-group differences in health utility scores diminished over time and were generally non-significant. The cabozantinib group accrued more QALYs than the placebo group over follow-up. Differences in mean QALYs (cabozantinib minus placebo) were statistically and clinically significant, ranging from +0.092 (95% CI: 0.016, 0.169) to +0.185 (95% CI: 0.126, 0.243) in favour of cabozantinib, depending on the reference value set used.
CONCLUSIONS: These HRQoL findings support a positive benefit-risk profile for cabozantinib in previously treated patients with aHCC
Reliability analysis of idealized tunnel support system using probability-based methods with case studies
Get PDFThe Paradox of Colour Constancy: Plotting the Lower Borders of Perception
Get PDFThis paper resolves a paradox concerning colour constancy. On the one hand, our intuitive, pre-theoretical concept holds that colour constancy involves invariance in the perceived colours of surfaces under changes in illumination. On the other, there is a robust scientific consensus that colour constancy can persist in cerebral achromatopsia, a profound impairment in the ability to perceive colours. The first stage of the solution advocates pluralism about our colour constancy capacities. The second details the close relationship between colour constancy and contrast. The third argues that achromatopsics retain a basic type of colour constancy associated with invariants in contrast processing. The fourth suggests that one person-level, conscious upshot of such processing is the visual awareness of chromatic contrasts āatā the edges of surfaces, implicating the ācolour for formā perceptual function. This primitive type of constancy sheds new light on our most basic perceptual capacities, which mark the lower borders of representational mind
Probabilistic Analysis of Pressurized Tunnels against Face Stability Using Collocation-Based Stochastic Response Surface Method
Full text linkLow intensity pulsed ultrasound (LIPUS) for bone healing: A clinical practice guideline
Get PDFDoes low intensity pulsed ultrasound (LIPUS) accelerate recovery in adults and children who have experienced bone fractures or osteotomy (cutting of a bone)? An expert panel rapidly produced these recommendations based on a linked systematic review triggered by a large multi-centre randomised trial in adults with tibial fracture
Effects of automated alerts on unnecessarily repeated serology tests in a cardiovascular surgery department: a time series analysis
Get PDF<p>Abstract</p> <p>Background</p> <p>Laboratory testing is frequently unnecessary, particularly repetitive testing. Among the interventions proposed to reduce unnecessary testing, Computerized Decision Support Systems (CDSS) have been shown to be effective, but their impact depends on their technical characteristics. The objective of the study was to evaluate the impact of a Serology-CDSS providing point of care reminders of previous existing serology results, embedded in a Computerized Physician Order Entry at a university teaching hospital in Paris, France.</p> <p>Methods</p> <p>A CDSS was implemented in the Cardiovascular Surgery department of the hospital in order to decrease inappropriate repetitions of viral serology tests (HBV).</p> <p>A time series analysis was performed to assess the impact of the alert on physicians' practices. The study took place between January 2004 and December 2007. The primary outcome was the proportion of unnecessarily repeated HBs antigen tests over the periods of the study. A test was considered unnecessary when it was ordered within 90 days after a previous test for the same patient. A secondary outcome was the proportion of potentially unnecessary HBs antigen test orders cancelled after an alert display.</p> <p>Results</p> <p>In the pre-intervention period, 3,480 viral serology tests were ordered, of which 538 (15.5%) were unnecessarily repeated. During the intervention period, of the 2,095 HBs antigen tests performed, 330 unnecessary repetitions (15.8%) were observed. Before the intervention, the mean proportion of unnecessarily repeated HBs antigen tests increased by 0.4% per month (absolute increase, 95% CI 0.2% to 0.6%, <it>p </it>< 0.001). After the intervention, a significant trend change occurred, with a monthly difference estimated at -0.4% (95% CI -0.7% to -0.1%, <it>p </it>= 0.02) resulting in a stable proportion of unnecessarily repeated HBs antigen tests. A total of 380 unnecessary tests were ordered among 500 alerts displayed (compliance rate 24%).</p> <p>Conclusions</p> <p>The proportion of unnecessarily repeated tests immediately dropped after CDSS implementation and remained stable, contrasting with the significant continuous increase observed before. The compliance rate confirmed the effect of the alerts. It is necessary to continue experimentation with dedicated systems in order to improve understanding of the diversity of CDSS and their impact on clinical practice.</p
Effective implementation of research into practice: an overview of systematic reviews of the health literature
Get PDF<p>Abstract</p> <p>Background</p> <p>The gap between research findings and clinical practice is well documented and a range of interventions has been developed to increase the implementation of research into clinical practice.</p> <p>Findings</p> <p>A review of systematic reviews of the effectiveness of interventions designed to increase the use of research in clinical practice. A search for relevant systematic reviews was conducted of Medline and the Cochrane Database of Reviews 1998-2009. 13 systematic reviews containing 313 primary studies were included. Four strategy types are identified: audit and feedback; computerised decision support; opinion leaders; and multifaceted interventions. Nine of the reviews reported on multifaceted interventions. This review highlights the small effects of single interventions such as audit and feedback, computerised decision support and opinion leaders. Systematic reviews of multifaceted interventions claim an improvement in effectiveness over single interventions, with effect sizes ranging from small to moderate. This review found that a number of published systematic reviews fail to state whether the recommended practice change is based on the best available research evidence.</p> <p>Conclusions</p> <p>This overview of systematic reviews updates the body of knowledge relating to the effectiveness of key mechanisms for improving clinical practice and service development. Multifaceted interventions are more likely to improve practice than single interventions such as audit and feedback. This review identified a small literature focusing explicitly on getting research evidence into clinical practice. It emphasizes the importance of ensuring that primary studies and systematic reviews are precise about the extent to which the reported interventions focus on changing practice based on research evidence (as opposed to other information codified in guidelines and education materials).</p
Visual adaptation and face perception
Get PDFThe appearance of faces can be strongly affected by the characteristics of faces viewed previously. These perceptual after-effects reflect processes of sensory adaptation that are found throughout the visual system, but which have been considered only relatively recently in the context of higher level perceptual judgements. In this review, we explore the consequences of adaptation for human face perception, and the implications of adaptation for understanding the neural-coding schemes underlying the visual representation of faces. The properties of face after-effects suggest that they, in part, reflect response changes at high and possibly face-specific levels of visual processing. Yet, the form of the after-effects and the norm-based codes that they point to show many parallels with the adaptations and functional organization that are thought to underlie the encoding of perceptual attributes like colour. The nature and basis for human colour vision have been studied extensively, and we draw on ideas and principles that have been developed to account for norms and normalization in colour vision to consider potential similarities and differences in the representation and adaptation of faces
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