396 research outputs found
Using Teaching Excellence Surveys to Evaluate Improvements in Teaching Confidence
BACKGROUND: There are many surveys to assess teaching excellence, but few validated tools to assess improvements in teaching confidence among faculty over time. We hypothesized that previously validated surveys for learner evaluation of faculty teaching excellence also can be used as a self-evaluation tool to assess changes in faculty teaching skills confidence over time. METHODS: A cohort study was designed using a composite survey from two previously validated surveys (SETQ and CanMEDS) on teaching excellence. The composite survey was administered before and after a faculty development course on teaching excellence at the University of Kansas Medical Center in the Spring of 2012. Course “completers” attended more than 50% of the course and “non-completers” attended 50% or less of the course. RESULTS: The overall mean change in survey result scores on a five-point Likert scale was nearly one point for “completers” (mean difference = 0.92, SD = 0.41) as opposed to 0.34 for “non-completers” (SD = 0.34, p = 0.001). The Cronbach’s alpha coefficients for the pre-course surveys were 0.83 and 0.85 versus 0.88 and 0.83 for the post-course surveys, indicating a high internal consistency for both survey instruments. CONCLUSIONS: Measurable improvements in teaching skills confidence occur following faculty professional development courses. These improvements can be assessed more efficiently by using previously validated and reliable assessment tools in new and innovative ways
Radiation exposure in X-ray-based imaging techniques used in osteoporosis
Recent advances in medical X-ray imaging have enabled the development of new techniques capable of assessing not only bone quantity but also structure. This article provides (a) a brief review of the current X-ray methods used for quantitative assessment of the skeleton, (b) data on the levels of radiation exposure associated with these methods and (c) information about radiation safety issues. Radiation doses associated with dual-energy X-ray absorptiometry are very low. However, as with any X-ray imaging technique, each particular examination must always be clinically justified. When an examination is justified, the emphasis must be on dose optimisation of imaging protocols. Dose optimisation is more important for paediatric examinations because children are more vulnerable to radiation than adults. Methods based on multi-detector CT (MDCT) are associated with higher radiation doses. New 3D volumetric hip and spine quantitative computed tomography (QCT) techniques and high-resolution MDCT for evaluation of bone structure deliver doses to patients from 1 to 3 mSv. Low-dose protocols are needed to reduce radiation exposure from these methods and minimise associated health risks
Preliminary Study of Prospective ECG-Gated 320-Detector CT Coronary Angiography in Patients with Ventricular Premature Beats
BACKGROUND: To study the applicability of prospective ECG-gated 320-detector CT coronary angiography (CTCA) in patients with ventricular premature beats (VPB), and determine the scanning mode that best maximizes image quality and reduces radiation dose. METHODS: 110 patients were divided into a VPB group (60 cases) and a control group (50 cases) using CTCA. All the patients then underwent coronary angiography (CAG) within one month. CAG served as a reference standard through which the sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) of CTCA in diagnosing significant coronary artery stenosis (luminal stenosis ≥50%) could be analyzed. The two radiologists with more than 3 years' experience in cardiac CT each finished the image analysis after consultation. A personalized scanning mode was adopted to compare image quality and radiation dose between the two groups. METHODOLOGY/PRINCIPAL FINDINGS: At the coronary artery segment level, sensitivity, specificity, PPV, and NPV in the premature beat group were 92.55%, 98.21%, 88.51%, and 98.72% respectively. In the control group these values were found to be 95.79%, 98.42%, 90.11%, and 99.28% respectively. Between the two groups, specificity, sensitivity PPV, NPV was no significant difference. The two groups had no significant difference in image quality score (P>0.05). Heart rate (77.20±12.07 bpm) and radiation dose (14.62±1.37 mSv) in the premature beat group were higher than heart rate (58.72±4.73 bpm) and radiation dose (3.08±2.35 mSv) in the control group. In theVPB group, the radiation dose (34.55±7.12 mSv) for S-field scanning was significantly higher than the radiation dose (15.10±1.12 mSv) for M-field scanning. CONCLUSIONS/SIGNIFICANCE: With prospective ECG-gated scanning for VPB, the diagnostic accuracy of coronary artery stenosis is very high. Scanning field adjustment can reduce radiation dose while maintaining good image quality. For patients with slow heart rates and good rhythm, there was no statistically significant difference in image quality
Die Rolle des Freibergerpferdes im Pferdemarkt Schweiz
Das Freiberger Pferd hat wie viele andere vergleichbare lokale, ursprüngliche europäische Pferderassen mit rückläufigen Bestandes- und Geburtenzahlen sowie einer fehlenden Rentabilität auf Stufe Produktion zu kämpfen. Agroscope,
Schweizer Nationalgestüt SNG, untersuchte im Zuge der Erarbeitung eines Strategierapportes zur Erhaltung der Freibergerrasse die Marktkonformität
des Freibergerpferdes (FM: franches-montagnes) mittels einer Umfrage bei Pferdeeigentümern sowie ergänzenden Experteninterviews. Die Ergebnisse lassen den Schluss zu, dass bei einer Mehrheit der befragten Pferdeeigentümer
die persönlichen Erwartungen an ein Pferd mit der Beurteilung der Qualitäten und der generellen Wahrnehmung des Freibergerpferdes deckungsgleich sind. Daraus lässt sich ableiten, dass der FM über Qualitäten verfügt, die im
Grundsatz im Freizeitpferdemarkt nachgefragt werden (einfacher Charakter, Polyvalenz, Robustheit, Gesundheit). Das Image des Markenbildes FM ist bei den nicht FM-Besitzern deutlich weniger positiv als bei den FM-Besitzern. Die Ergebnisse der Umfrage sowie der Experteninterviews zeigten, dass vor allem Anstrengungen zur Verbesserung der Vermarktung und des Images notwendig sind, um einen besseren Absatz von Freibergerpferden zu gewährleisten und damit auch langfristig einen Anstieg der Geburten zu erreichen
Reduction of artefacts caused by hip implants in CT-based attenuation-corrected PET images using 2-D interpolation of a virtual sinogram on an irregular grid
Metallic prosthetic replacements, such as hip or knee implants, are known to cause strong streaking artefacts in CT images. These artefacts likely induce over- or underestimation of the activity concentration near the metallic implants when applying CT-based attenuation correction of positron emission tomography (PET) images. Since this degrades the diagnostic quality of the images, metal artefact reduction (MAR) prior to attenuation correction is required
S3-TM: scalable streaming short text matching
Micro-blogging services have become major venues for information creation, as well as channels of information dissemination. Accordingly, monitoring them for relevant information is a critical capability. This is typically achieved by registering content-based subscriptions with the micro-blogging service. Such subscriptions are long-running queries that are evaluated against the stream of posts. Given the popularity and scale of micro-blogging services like Twitter and Weibo, building a scalable infrastructure to evaluate these subscriptions is a challenge. To address this challenge, we present the S3-TM system for streaming short text matching. S3-TM is organized as a stream processing application, in the form of a data parallel flow graph designed to be run on a data center environment. It takes advantage of the structure of the publications (posts) and subscriptions to perform the matching in a scalable manner, without broadcasting publications or subscriptions to all of the matcher instances. The basic design of S3-TM uses a scoped multicast for publications and scoped anycast for subscriptions. To further improve throughput, we introduce publication routing algorithms that aim at minimizing the scope of the multicasts. First set of algorithms we develop are based on partitioning the word co-occurrence frequency graph, with the aim of routing posts that include commonly co-occurring words to a small set of matchers. While effective, these algorithms fell short in balancing the load. To address this, we develop the SALB algorithm, which provides better load balance by modeling the load more accurately using the word-to-post bipartite graph. We also develop a subscription placement algorithm, called LASP, to group together similar subscriptions, in order to minimize the subscription matching cost. Furthermore, to achieve good scalability for increasing number of nodes, we introduce techniques to handle workload skew. Finally, we introduce load shedding techniques for handling unexpected load spikes with small impact on the accuracy. Our experimental results show that S3-TM is scalable. Furthermore, the SALB algorithm provides more than 2.5× throughput compared to the baseline multicast and outperforms the graph partitioning-based approaches. © 2015, Springer-Verlag Berlin Heidelberg
The future of hybrid imaging—part 2: PET/CT
Since the 1990s, hybrid imaging by means of software and hardware image fusion alike allows the intrinsic combination of functional and anatomical image information. This review summarises the state-of-the-art of dual-modality imaging with a focus on clinical applications. We highlight selected areas for potential improvement of combined imaging technologies and new applications. In the second part, we briefly review the background of dual-modality PET/CT imaging, discuss its main applications and attempt to predict technological and methodological improvements of combined PET/CT imaging. After a decade of clinical evaluation, PET/CT will continue to have a significant impact on patient management, mainly in the area of oncological diseases. By adopting more innovative acquisition schemes and data processing PET/CT will become a fast and dose-efficient imaging method and an integral part of state-of-the-art clinical patient management
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