212 research outputs found
Shading Curves: Vector-Based Drawing With Explicit Gradient Control
A challenge in vector graphics is to define primitives that offer flexible manipulation of colour gradients. We propose a new primitive, called a shading curve, that supports explicit and local gradient control. This is achieved by associating shading profiles to each side of the curve. These shading profiles, which can be manually manipulated, represent the colour gradient out from their associated curves. Such explicit and local gradient control is challenging to achieve via the diffusion curve process, introduced in 2008, because it offers only implicit control of the colour gradient. We resolve this problem by using subdivision surfaces that are constructed from shading curves and their shading profiles.This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1111/cgf.1253
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School-Based Telemedicine Interventions for Asthma: A Systematic Review.
BackgroundSchool health systems are increasingly investing in telemedicine platforms to address acute and chronic illnesses. Asthma, the most common chronic illness in childhood, is of particular interest given its high burden on school absenteeism.ObjectiveConduct a systematic review evaluating impact of school-based telemedicine programs on improving asthma-related outcomes.Data sourcesPubMed, Cochrane CENTRAL, CINAHL, ERIC, PsycINFO, Embase, and Google Scholar.Study eligibility criteriaOriginal research, including quasi-experimental studies, without restriction on the type of telemedicine.ParticipantsSchool-aged pediatric patients with asthma and their families.InterventionsSchool-based telemedicine.Study appraisal and synthesis methodsTwo authors independently screened each abstract, conducted full-text review, assessed study quality, and extracted information. A third author resolved disagreements.ResultsOf 371 articles identified, 7 were included for the review. Outcomes of interest were asthma symptom-free days, asthma symptom frequency, quality of life, health care utilization, school absences, and spirometry. Four of 7 studies reported significant increases in symptom-free days and/or decrease in symptom frequency. Five of 6 reported increases in at least one quality-of-life metric, 2 of 7 reported a decrease in at least 1 health care utilization metric, 1 of 3 showed reductions in school absences, and 1 of 2 reported improvements in spirometry measures.LimitationsVariability in intervention designs and outcome measures make comparisons and quantitative analyses across studies difficult. Only 2 of 7 studies were randomized controlled trials.Conclusions and implications of key findingsHigh-quality evidence supporting the use of school-based telemedicine programs to improve patient outcomes is limited. While available evidence suggests benefit, only 2 comparative trials were identified, and the contribution of telemedicine to these studies' results is unclear
Cornsweet surfaces for selective contrast enhancement
A typical goal when enhancing the contrast of images is to increase the perceived contrast without altering the original feel of the
image. Such contrast enhancement can be achieved by modelling Cornsweet profiles into the image. We demonstrate that previous
methods aiming to model Cornsweet profiles for contrast enhancement, often employing the unsharp mask operator, are not robust
to image content. To achieve robustness, we propose a fundamentally di erent vector-centric approach with Cornsweet surfaces.
Cornsweet surfaces are parametrised 3D surfaces (2D in space, 1D in luminance enhancement) that are extruded or depressed in
the luminance dimension to create countershading that respects image structure. In contrast to previous methods, our method is
robust against the topology of the edges to be enhanced and the relative luminance across those edges. In user trials, our solution
was significantly preferred over the most related contrast enhancement method.Kosinka was funded by EPSRC grant EP/H024816/1. Lieng was funded by a scholarship from the Norwegian Government.This is the accepted manuscript. The final version is available from Elsevier at http://www.sciencedirect.com/science/article/pii/S0097849314000405
Pericardial Thickness Measured With Transesophageal Echocardiography: Feasibility and Potential Clinical Usefulness
AbstractObjectives. This study assessed the reliability of transesophageal echocardiographic measurements of pericardial thickness and the potential diagnostic usefulness of this technique.Background. Transthoracic echocardiography cannot reliably detect thickened pericardium. The superior resolution achieved with transesophageal echocardiography should allow better pericardial definition.Methods. Pericardial thickness measured at 26 locations in 11 patients with constrictive pericarditis who underwent intraoperative transesophageal echocardiography was compared with pericardial thickness measured with electron beam computed tomography. Intraobserver and interobserver variabilities were determined. Pericardial thickness was then measured in 21 normal subjects. With these values as a guide, two observers reviewed 37 transesophageal echocardiographic studies to determine whether echocardiographic measurement of pericardial thickness could be used to distinguish diseased from normal pericardium.Results. The correlation between echocardiographic and computed tomographic measurements (r â„ 0.95, SE †0.06 mm, p < 0.0001) was excellent. The ±2 SD limits of agreement were ±1.0 mm or less for pericardial thickness <5.5 mm and ±2.0 mm or less for the entire range of thicknesses. Intraobserver and interobserver agreements were good. Mean normal pericardial thickness was 1.2 ± 0.8 mm (±2 SD) and did not exceed 2.5 mm. Pericardial thickness â„3 mm on transesophageal echocardiography was 95% sensitive and 86% specific for the detection of thickened pericardium.Conclusions. Measurement of pericardial thickness with transesophageal echocardiography is reproducible and should be a valuable adjunct in assessing constrictive pericarditis.(J Am Coll Cardiol 1997;29:1317â23
Shorter GT repeats in the heme oxygenase-1 gene promoter are associated with a lower severity score in coronary artery disease
Abstract Background: The glutathione thymidine repeats [(GT) n ] of the heme oxygenase (HO)-1 gene promoter have been shown to be correlated with the incidence of coronary artery disease (CAD), patients with shorter repeats being less likely to have CAD. In this study, we investigated whether (GT) n repeats in the HO-1 promoter were related to a quantitative angiographic severity of CAD. Methods: The allele frequency of the HO-1 gene promoter (GT) n repeats was examined in CAD patients with de novo lesions (n Œ 328). Patients' baseline coronary severity was quantified using the Jeopardy scoring system. Results: The allele frequency of GT repeats in the HO-1 gene promoter had bimodal peaks at (GT) 23 and (GT) 30. Therefore, we defined allele classes as follows: S allele (<23 repeats), M allele (23e29 repeats), and L allele (!30 repeats). The group with severe CAD (Jeopardy score !8) had a significantly lower frequency of the S allele (3.7% vs. 8.9%; p Œ 0.042) than the group with moderate CAD (Jeopardy score <8). None of the patient with the highest score of 12 (n Œ 17) carried the class S allele. In a multivariate binary logistic analysis, being a carrier of shorter GT repeats was a significant negative predictor (odds ratio 0.393; p Œ 0.024) of a higher Jeopardy score grade of CAD. Conclusion: Our study showed that shorter (GT) n repeat in the HO-1 gene promoter were associated with a lower Jeopardy severity score in patients with significant CAD
Current practice in the removal of benign endometrial polyps: a Dutch survey
The purpose of this study is to evaluate the current practice of Dutch gynecologists in the removal of benign endometrial polyps and compare these results with the results of a previous study from 2003. In 2009 Dutch gynecologists were surveyed by a mailed questionnaire about polypectomy. Gynecologists answered questions about their individual performance of polypectomy: setting, form of anesthesia, method, and instrument use. The results were compared with the results from the previous survey. The response rate was 70% (585 of 837 gynecologists). Among the respondents, 455 (78%) stated to remove endometrial polyps themselves. Polyps were mostly removed in an inpatient setting (337; 74%) under general or regional anesthesia (247; 54%) and under direct hysteroscopic vision (411; 91%). Gynecologists working in a teaching hospital removed polyps more often in an outpatient setting compared with gynecologists working in a nonteaching hospital [118 (43%) vs. 35 (19%) pâ<â0.001]. These results are in accordance with the results from 2003. Compared to 2003 there was an increase in the number of gynecologists performing polypectomies with local or no anesthesia [211 (46%) vs. 98 (22%), pâ<â0.001]. An increase was also noted in the number of gynecologists using direct hysteroscopic vision [411 (91%) vs. 290 (64%), pâ<â0.001] and 5 Fr electrosurgical instruments [181 (44%) vs. 56 (19%), pâ<â0.001]. Compared to the situation in 2003, there is an increase in removal under direct hysteroscopic vision, with 5 Fr electrosurgical instruments, using local or no anesthesia. This implies there is progress in outpatient hysteroscopic polypectomy in the Netherlands
Opposite-side flavour tagging of B mesons at the LHCb experiment
The calibration and performance of the oppositeside
flavour tagging algorithms used for the measurements
of time-dependent asymmetries at the LHCb experiment
are described. The algorithms have been developed using
simulated events and optimized and calibrated with
B
+ âJ/ÏK
+, B0 âJ/ÏK
â0 and B0 âD
ââ
Ό
+
ΜΌ decay
modes with 0.37 fbâ1 of data collected in pp collisions
at
â
s = 7 TeV during the 2011 physics run. The oppositeside
tagging power is determined in the B
+ â J/ÏK
+
channel to be (2.10 ± 0.08 ± 0.24) %, where the first uncertainty
is statistical and the second is systematic
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