3,690 research outputs found
The development of a mapping tool for the evaluation of building systems for future climate scenarios on European scale
The paper presents a tool for the mapping of the performance of building
systems on European scale for different (future) time periods. The tool is to
use for users and be applicable for different building systems. Users should
also be able to use a broad range of climate parameters to assess the influence
of climate change on these climatic parameters. Also should the calculation
time be reasonable short. The mapping tool is developed in MATLAB, which can be
used by other users for their own studies.Comment: 21 pages, 24 figures, pre-conferenc
What have we learned from in vitro intravascular ultrasound?
In vitro studies have established that intravascular ultrasound is a reliable technique for accurate assessment of vascular anatomic structure and disease conditions before and after intervention. In addition, quantitative data from intravascular ultrasound studies correspond well with histologic findings, which serve as the gold standard. These in vitro studies permit the understanding and interpretation of ultrasound images obtained in vivo, although differences between the two settings should be taken into account. New ultrasound modalities currently being developed may enhance the diagnostic differentiation of plaque morphologic characteristics and facilitate on-line quantitative assessment of vessel structure
Movers and shakers of cognition:Hand movements, speech, task properties, and variability
Children move their hands to explore, learn and communicate about hands-on tasks. Their hand movements seem to be “learning” ahead of speech. Children shape their hand movements in accordance with spatial and temporal task properties, such as when they feel an object or simulate its movements. Their speech does not directly correspond to these spatial and temporal task properties, however. We aimed to understand whether and how hand movements' are leading cognitive development due to their ability to correspond to spatiotemporal task properties, while speech is unable to do so. We explored whether hand movements' and speech's variability changed with a change in spatiotemporal task properties, using two variability measures: Diversity indicates adaptation, while Complexity indicates flexibility to adapt. In two experiments, we asked children (4–7 years) to predict and explain about balance scale problems, whereby we either manipulated the length of the balance scale or the mass of the weights after half of the trials. In three out of four conditions, we found a change in Complexity for both hand movements and speech between first and second half of the task. In one of these conditions, we found a relation between the differences in Complexity and Diversity of hand movements and speech. Changes in spatiotemporal task properties thus often influenced both hand movements' and speech's flexibility, but there seem to be differences in how they did so. We provided many directions for future research, to further unravel the relations between hand movements, speech, task properties, variability, and cognitive development
Evaluating Animal-Assisted Interventions:An Empirical Illustration of Differences between Outcome Measures
Multiple authors have called for strong empirical evaluations to strengthen the foundation of Animal-Assisted Interventions. Carefully choosing the outcome measures of these studies is important, as choosing the wrong outcomes may lead to a failure to detect effects. The current study therefore compares and contrasts the use of several outcome measures, to assess the effect of an equine-assisted intervention for a child with Autism Spectrum Disorder: (1) a semi-structured interview with both parents, specifically designed for children with cognitive disabilities, (2) a general screening instrument filled out by both parents separately, which can be used to assess children’s psycho-social problems, and (3) systematic observations of social and communication skills during the equine-assisted sessions. All instruments indicated an improvement in the participant’s social and communication skills. We found differences between the interview and questionnaires with regard to parents’ perception of aggression regulation and interacting with peers. Differences with regard to parental reports and observations were found for play development and anxiety. The observations provided a detailed view of the child’s development during the intervention, which yielded an interesting hypothesis in terms of the current dose–response discussion in AAI for children with Autism Spectrum Disorder
Model-based cap thickness and peak cap stress prediction for carotid MRI
A rupture-prone carotid plaque can potentially be identified by calculating the peak cap stress (PCS). For these calculations, plaque geometry from MRI is often used. Unfortunately, MRI is hampered by a low resolution, leading to an overestimation of cap thickness and an underestimation of PCS. We developed a model to reconstruct the cap based on plaque geometry to better predict cap thickness and PCS. We used histological stained plaques from 34 patients. These plaques were segmented and served as the ground truth. Sections of these plaques contained 93 necrotic cores with a cap thickness <0.62 mm which were used to generate a geometry-based model. The histological data was used to simulate in vivo MRI images, which were manually delineated by three experienced MRI readers. Caps below the MRI resolution (n = 31) were (digitally removed and) reconstructed according to the geometry-based model. Cap thickness and PCS were determined for the ground truth, readers, and reconstructed geometries. Cap thickness was 0.07 mm for the ground truth, 0.23 mm for the readers, and 0.12 mm for the reconstructed geometries. The model predicts cap thickness significantly better than the readers. PCS was 464 kPa for the ground truth, 262 kPa for the readers and 384 kPa for the reconstructed geometries. The model did not predict the PCS significantly better than the readers. The geometry-based model provided a significant improvement for cap thickness estimation and can potentially help in rupture-risk prediction, solely based on cap thickness. Estimation of PCS estimation did not improve, probably due to the complex shape of the plaques
Intravascular Palpography for Vulnerable Plaque Assessment
Palpography assesses the local mechanical properties of tissue using the deformation caused by the intraluminal pressure. The technique was validated in vitro using diseased human coronary and femoral arteries. Especially between fibrous and fatty tissue, a highly significant difference in strain (p = 0.0012) was found. Additionally, the predictive value to identify the vulnerable plaque was investigated. A high-strain region at the lumen vessel wall boundary has 88% sensitivity and 89% specificity for identifying these plaques. In vivo, the technique is validated in an atherosclerotic Yucatan minipig animal model. This study also revealed higher strain values in fatty than in fibrous plaques (p < 0.001). The presence of a high-strain region at the lumen-plaque interface has a high predictive value to identify macrophages. Patient studies revealed high strain values (1% to 2%) in noncalcified plaques. Calcified material showed low strain values (0% to 0.2%). With the development of three-dimensional palpography, identification of weak spots over the full length of a coronary artery becomes available. Patients with myocardial infarction or unstable angina have more high-strain spots in their coronary arteries than patients with stable angina. In conclusion, intravascular palpography is a unique tool to assess lesion composition and vulnerability. Three-dimensional palpography provides a technique that may develop into a clinically available tool for decision making to treat hemodynamically nonsignificant lesions by identifying vulnerable plaques. The clinical utility of this technique is yet to be determined, and more investigation is needed
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