Structure formation during spinning of poly(p-phenylenebenzobisthiazole) fiber

The structure formed in the coagulation stage of the spinning process of poly(p-phenylene benzobisthiazole) fiber is studied by electron microscopy. An oriented network of microfibrils with typical fibril diameters of about 80-100Å is observed. We suggest that these microfibrils are the fundamental structural elements of the fiber. Thus, knowledge of the mechanism by which this initial structure is formed may allow for better control of final fiber properties. The relation of structure formation during coagulation to the phase diagram of a rigid polymer solution and to the kinetic mechanism of the phase transition is discussed.     

Online scheduling and placement of hardware tasks with multiple variants on dynamically reconfigurable field-programmable gate arrays

Hardware task scheduling and placement at runtime plays a crucial role in achieving better system performance by exploring dynamically reconfigurable Field-Programmable Gate Arrays (FPGAs). Although a number of online algorithms have been proposed in the literature, no strategy has been engaged in efficient usage of reconfigurable resources by orchestrating multiple hardware versions of tasks. By exploring this flexibility, on one hand, the algorithms can be potentially stronger in performance; however, on the other hand, they can suffer much more runtime overhead in selecting dynamically the best suitable variant on-the-fly based on its runtime conditions imposed by its runtime constraints. In this work, we propose a fast efficient online task scheduling and placement algorithm by incorporating multiple selectable hardware implementations for each hardware request; the selections reflect trade-offs between the required reconfigurable resources and the task runtime performance. Experimental studies conclusively reveal the superiority of the proposed algorithm in terms of not only scheduling and placement quality but also faster runtime decisions over rigid approaches.     

Synthesis of transparent fluorocarbon elastomers: Effect of crosslinker type and electron beam irradiation level on physical and mechanical behavior

Saturated fluorocarbon elastomers are very resistant to chemical reactions, including those of a crosslinking nature. In order to study proper methods of preparing these materials, Viton GLT was mixed with various levels of trimethylol propane trimethacrylate, TMPTM, and triallyl isocyanurate, Diak #7. After molding, the materials were subjected to electron beam irradiation. The glass transition, rubbery modulus, viscoelastic behavior, and equilibrium swelling were used to characterize the materials as a function of crosslinker and irradiation level. In general, the modulus and gel fraction increased with both crosslinker content and irradiation level. Mixtures of both crosslinking monomers produced an unexpected synergism, yielding higher tensile strength, and earlier onset of gelation.     

Bark beetle olfaction. III. Antennal olfactory responsiveness ofDendroctonus frontalis Zimmerman andD. brevicomis Le Conte (Coleoptera: Scolytidae) to aggregation pheromones and host tree terpene hydrocarbons

Electroantennograms from males and females ofDendroctonus frontalis andD. brevicomis in response to serial dilutions of the pheromonesexo brevicomin and frontalin and the host terpene hydrocarbons 3-carene and α-pinene show no significant differences in the threshold concentration for response to the compounds for either sex or species. The intensity of response was greater to higher concentrations of the pheromones (10 to >10⁴ μg) than the terpene hydrocarbons, suggesting the presence of more receptors on the antennae for pheromones than terpene hydrocarbons. Antennal olfactory responses to the compounds did not correlate to published data on behavioral responses by the beetles to the compounds in both field and laboratory studies. Adaptation experiments indicated that forD. frontalis, both frontalin andexo brevicomin share the same receptors on the antennae. The results indicated that the terpene hydrocarbons share some, but not all, of the same receptors.     

Effect of lecithin on jejunal absorption of micellar lipids in man and on their monomer activity in vitro

The effect of lecithin on jejunal absorption of fatty acids and octadecenoylglycerol was studied in healthy volunteers with a jejunal perfusion system which excluded pancreatic and biliary secretions from the test segment. Lecithin significantly reduced the absorption of oleic acid (P<0.05) and octadecenoylglycerol (P<0.01), while it had no effect on the absorption of ricinoleic acid. In vitro, lecithin reduced monomer activities of all three lipids; the changes were greater for oleic acid and octadecenoylglycerol than for ricinoleic acid (P<0.02). From these data it is concluded that lecithin reduces monomer activity of fatty acids in mixed micellar solutions and that it can thereby reduce the absorption rates of micellar lipids. Intact lecithin is not absorbed under these conditions. Maldigestion of lecithin in pancreatic insufficiency may, therefore, aggravate the steatorrhea observed in this condition.     

Fast template tracking in video sequences

Tracking of poorly defined, rotating and/or distorted objects in a video sequence poses significant problems especially in medical diagnostics including ultrasound (sonographic) video used for examination and diagnosis of internal movement of tissue or muscle and nerve action. Cross-correlation techniques have been successful in retrieving dynamic information directly from ultrasound video data. We outline a fast implementation of tracking based on normalized cross-correlation using an adaptive template and present results from our application, developed in MATLAB?, which successfully tracks arbitrarily selected objects in deformed or severely compromised images. Common ultrasound image evaluation is qualitative but there is need to retrieve quantitative dynamic information such as the trajectory or velocity of selected areas. Our approach uses normalized two-dimensional cross-correlation to find the position of an initially selected template enclosing the feature of interest and map its trajectory frame-by-frame to produce displacement and velocity plots. We illustrate operation of the application using routine ultrasound data and demonstrate its performance using test video of objects rotating full circle and rolling down a ramp. We analyse errors associated with sampling to compare performance of our implementation with a more rigorous but tedious and computationally expensive correlation of a resampled, rotated, and shifted template.     

Building Trust and Cooperation through Technology Adaptation in Virtual Teams: Empirical Field Evidence

Abstract

This article reports findings of a study of how leaders of virtual information systems development teams improve team trust and cooperation by managing adaptation of information and communications tools. Results indicate how Theory X (command and control) and Theory Y (facilitate and support) styles of leadership enable and hinder effective outcomes.     

An interactive lung field segmentation scheme with automated capability

Feasible clinical application of any automated segmenting methodology demands more than just accuracy. Amendment to the automated delineation is necessary when the algorithm fails, however, integrated solution to such a scenario is largely absent in literature. Hence in this survey we devised an architecture that does both the automated and interactive lung field localizations using a single segmenting engine—random walker algorithm—so that intuitive amendment is only necessary when the automated generated delineation is unsatisfactory. The algorithm proceeds by first extracting 18 intensity profiles running horizontally, each of them equally spacing apart, and in each intensity profile three extreme points denoting the two lungs and the esophagus are determined through profile matching. This done, the algorithm removes profiles that do not intersect with the lung, and the rest of the extreme points are plugged into random walker algorithm to perform segmentation. The achieved accuracy in localization by the above was 0.8875 in terms of overlap measure (the maximum value for this parameter is 1) over 341 images. In the case where unsatisfactory delineation prompts amendment necessary, the user can interactively segment the lung by just a shift on some of the previous-determined points to the desired locations, and random walker algorithm is run again with the amended input. By such a fusion, the benefits of both the automated and interactive segmentation are shared in a single architecture.     

EVALUATING THE IMPACT OF THE INSTITUTIONAL REPOSITORY,OR POSITIONING INNOVATION BETWEEN A ROCK AND A HARD PLACE

Repositories remain an innovative but marginalised technology largely because there is no consensus about an agreed set of Performance Indicators (PIs) that demonstrate their overall impact on the research enterprise of our universities. A successful institutional repository (IR) should be evaluated in terms of the extent to which the open access repository builds a critical mass of scholarly content which is sustained and available through active university community engagement and ongoing scholarly contributions (faculty, researchers and students) that, when managed efficiently and effectively, ultimately strengthen, promote and give visibility to the research enterprise of the institution, and bring benefit to broader society. However, librarians are grappling with what and how best to demonstrate ‘institutional good’ but without clear evidence, assessment is fed by perception based on limited information which leads to diminished impact and value of the facility, a tyranny described as being caught between a rock and a hard place. Using Illuminative Evaluation to design a series of quantitative and qualitative metrics, it is proposed that a distinction be made between significant and secondary PIs where the former gather evidence to demonstrate the overall effect or impact of the IR on the individual and collective research community.