Analysis Of the Performance Of Iodinated Contrast X-Ray Attenuator Under Physiologically Relevant Conditions

X-ray is a radiological tool utilized in healthcare institutions around the world to diagnose abnormalities such as bone fractures or the presence of foreign material within patients. The ability for healthcare providers to properly diagnose a problem is improved with advancements in the quality of radiological images. One way to improve image quality is to optimize the contrast range within a single image created by different attenuating characteristics in various types of tissue. In this study, I used a proof-of-concept prototype model of an x-ray attenuation system and an experimental protocol to examine its capacity to equalize x-ray beam signal values. A scout object consisting of different thicknesses of aluminum with the thickest section representing the most attenuated section and the target for equalization was used as a model of different types of tissue in a patient. The performance of the device and procedure was studied at various x-ray power levels and base acrylic thicknesses to represent anatomically relevant conditions. The different base acrylic thicknesses were used to represent standard attenuation in different sized patients. A statistical analysis was conducted using an unpaired t-test on the data results to identify whether the results are statistically significant and represent an improvement in image quality. The calibration equations developed to calculate the amount of iodinated contrast necessary at certain conditions were tested at intermediate levels to test performance under other conditions. The unpaired t-test was also conducted on these results. The analysis showed the exposure levels in each column were optimized to reduce the dynamic range of signal values

Transferring a Question-Based Dialog Framework to a Distributed Architecture

Inquiry skills are an essential tool for assessing and integrating knowledge. In facilitated face-to-face settings, inquiry skills were improved successfully by using a “question-based dialog” and its resulting visual representation. However, groups that work without a facilitator, or in which members collaborate asynchronously or in different geographical regions, such as Communities of Practice (CoP), cannot schedule face-to-face inquiry meetings. This paper summarises the unmet requirements of CoPs for a collaborative inquiry tool found by previous research on the Noracle model and proposes a distributed Web architecture as a solution. It mitigates the need for a common infrastructure, central coordination or facilitation, addresses the evolutionary nature of communities of practice and reduces the cognitive load for the individual by filtering and organising the representational artefacts with respect to the social network of the community. The implementation we envision in this paper aims at applying the concept to a much broader audience, ultimately replacing the need for local meetings

Comparison of Oak and Sugar Maple Distribution and Regeneration in Central Illinois Upland Oak Forests

Although white oak (Quercus alba) dominated much of the mid-west and eastern US hardwood forests prior to European settlement, changes in disturbance frequencies and habitat fragmentation, coupled with other biotic pressures, are allowing sugar maple (Acer saccharum Marshall) to displace oak in the upland forest understory. Since our understanding of how disturbance mechanisms influence oak regeneration is not fully clear, there is lack of consensus on how to employ management practices. We collected seedling microhabitat data from 5 upland oak forest sites in central Illinois, each differing in age class and/or silvicultural treatment to determine: 1) Whether species of tree seedlings are selectively recruiting into specific microhabitats, 2) Whether silvicultural treatment results in changes in microhabitat at the stand scale, and 3) Whether silvicultural treatments alter seedling-environment relationships. Despite different management histories, oak and maple seedling densities were not significantly different among sites. Results of a MANOVA showed significant relationship between understory oak and maple distributions with slope position (\u3c0.0001) and a slope x aspect interaction (0.0189). Maples were more prevalent in mesic slope and aspect positions. A PCA for environmental variables followed with MANOVA by site showed the environmental relationships among species was consistent across sites. At each site, oaks typically separated from sugar maples suggesting environmental variables influence distribution regardless of site history. Results suggest that management intensity for oak in upland forests could be based on landscape position. Maple expansion may be reduced by concentrating mechanical treatments in expected areas of maple colonization, while continually using fire throughout stands to promote oak regeneration

Mass transfer enhancement produced by laser induced cavitation

A microelectrode is used to measure the mass transfer perturbation and characteristics during the growth and subsequent collapse of a single bubble (which, following its initial expansion, achieved a maximum radius, Rm, of not, vert, similar500–1000 ?m). This mass transfer enhancement was associated with the forced convection, driven by bubble motion, as the result of a single cavitation event generated by a laser pulse beneath a 25 ?m diameter Au microelectrode. Evidence for bubble growth and rebound is gained from the electrochemical and acoustic measurements. This is supported with high-speed video footage of the events generated. A threshold for the formation of large cavitation bubbles in electrolyte solutions is suggested

THE IMPORTANCE OF GOVERNANCE STRUCTURES IN IT PROJECT PORTFOLIO MANAGEMENT

Although recently a lot of attention has been devoted to IT project portfolio management in theory as well as in practice, research in this area is particularly focused on approaches for project selection. Related tasks and especially the organizational environment in which IT project portfolio management is embedded are often excluded. This paper relates existing findings from the field of IT governance to the field of IT project portfolio management. Based on a qualitative study, different fields of activities in IT project portfolio management are identified. Furthermore, governance issues in IT project portfolio management are illustrated and a category schema for the assessment of governance structures in the different fields of activities is introduced. In contrast to existing publications in this field of research, which usually employ a maturity level perspective, the paper focuses on the advantages and disadvantages of centralized, decentralized and federal structures in different fields of activities of IT project portfolio management. The paper is intended to highlight why different degrees of centralization in IT project portfolio management can be observed in practice

The role of first- and second-order stimulus features for human overt attention

When processing complex visual input, human observers sequentially allocate their attention to different subsets of the stimulus. What are the mechanisms and strategies that guide this selection process? We investigated the influence of various stimulus features on human overt attention—that is, attention related to shifts of gaze with natural color images and modified versions thereof. Our experimental modifications, systematic changes of hue across the entire image, influenced only the global appearance of the stimuli, leaving the local features under investigation unaffected. We demonstrated that these modifications consistently reduce the subjective interpretation of a stimulus as "natural” across observers. By analyzing fixations, we found that first-order features, such as luminance contrast, saturation, and color contrast along either of the cardinal axes, correlated to overt attention in the modified images. In contrast, no such correlation was found in unmodified outdoor images. Second-order luminance contrast ("texture contrast”) correlated to overt attention in all conditions. However, although none of the second-order color contrasts were correlated to overt attention in unmodified images, one of the second-order color contrasts did exhibit a significant correlation in the modified images. These findings imply, on the one hand, that higher-order bottom-up effects—namely, those of second-order luminance contrast—may partially account for human overt attention. On the other hand, these results also demonstrate that global image properties, which correlate to the subjective impression of a scene being "natural,” affect the guidance of human overt attentio

Event Entry Time Prediction in Financial Business Processes Using Machine Learning - A Use Case From Loan Applications

The recent financial crisis has forced politics to overthink regulatory structures and compliance mechanisms for the financial industry. Faced with these new challenges the financial industry in turn has to reevaluate their risk assessment mechanisms. While approaches to assess financial risks, have been widely addressed, the compliance of the underlying business processes is also crucial to ensure an end-to-end traceability of the given business events. This paper presents a novel approach to predict entry times and other key performance indicators of such events in a business process. A loan application process is used as a data example to evaluate the chosen feature modellings and algorithms