TRial of an Educational intervention on patients' knowledge of Atrial fibrillation and anticoagulant therapy, INR control, and outcome of Treatment with warfarin (TREAT)

Background Atrial fibrillation (AF) patients with a high risk of stroke are recommended anticoagulation with warfarin. However, the benefit of warfarin is dependent upon time spent within the target therapeutic range (TTR) of their international normalised ratio (INR) (2.0 to 3.0). AF patients possess limited knowledge of their disease and warfarin treatment and this can impact on INR control. Education can improve patients' understanding of warfarin therapy and factors which affect INR control. Methods/Design Randomised controlled trial of an intensive educational intervention will consist of group sessions (between 2-8 patients) containing standardised information about the risks and benefits associated with OAC therapy, lifestyle interactions and the importance of monitoring and control of their International Normalised Ratio (INR). Information will be presented within an 'expert-patient' focussed DVD, revised educational booklet and patient worksheets. 200 warfarin-naïve patients who are eligible for warfarin will be randomised to either the intervention or usual care groups. All patients must have ECG-documented AF and be eligible for warfarin (according to the NICE AF guidelines). Exclusion criteria include: aged < 18 years old, contraindication(s) to warfarin, history of warfarin USE, valvular heart disease, cognitive impairment, are unable to speak/read English and disease likely to cause death within 12 months. Primary endpoint is time spent in TTR. Secondary endpoints include measures of quality of life (AF-QoL-18), anxiety and depression (HADS), knowledge of AF and anticoagulation, beliefs about medication (BMQ) and illness representations (IPQ-R). Clinical outcomes, including bleeding, stroke and interruption to anticoagulation will be recorded. All outcome measures will be assessed at baseline and 1, 2, 6 and 12 months post-intervention. Discussion More data is needed on the clinical benefit of educational intervention with AF patients receiving warfarin. Trial registration ISRCTN93952605

Philosophy, theory, and practice of green operations management

This paper proposes a more profound discussion of the philosophical underpins of sustainability than currently exists in the MOT literature and considers their influence on the construction of the theories on green operations and technology management. Ultimately, it also debates the link between theory and practice on this subject area. The paper is derived from insights gained in three research projects completed during the past twelve years, primarily involving the first author. From 2000 to 2002, an investigation using scenario analysis, aimed at reducing atmospheric pollution in urban centres by substituting natural gas for petrol and diesel, provided the first set of insights about public policy, environmental impacts, investment analysis, and technological feasibility. The second research project, from 2003 to 2005, using a survey questionnaire, was aimed at improving environmental performance in livestock farming and explored the issues of green supply chain scope, environmental strategy and priorities. Finally, the third project, from 2006 to 2011, investigated environmental decisions in manufacturing organisations through case study research and examined the underlying sustainability drivers and decision-making processes. By integrating the findings and conclusions from these projects, the link between philosophy, theory, and practice of green operations and technology management is debated. The findings from all these studies show that the philosophical debate seems to have little influence on theory building so far. For instance, although ‘sustainable development’ emphasises ‘meeting the needs of current and future generation’, no theory links essentiality and environmental impacts. Likewise, there is a weak link between theory and the practical issues of green operations and technology management. For example, the well-known ‘life-cycle analysis’ has little application in many cases because the life cycle of products these days is dispersed within global production and consumption systems and there are different stakeholders for each life cycle stage. The results from this paper are relevant to public policy making and corporate environmental strategy and decision making. Most of the past and current studies in the subject of green operations and sustainability management deal with only a single sustainability dimension at any one time. Here the value and originality of this paper lies in its integration between philosophy, theory, and practice of green technology and operations management.

All change? Managers' experience of organizational change in theory and practice

Purpose - This paper aims to examine the usefulness of organizational change theory for management practice. Design/methodology/approach - The authors present an exploratory, empirical study of managers who were taught organizational change theory as part of a postgraduate degree. Building on the study findings, they analyse managers' subsequent experiences of organizational change; of how they use change theory in practice and the impact on their practice of their earlier formal study. Findings - The paper finds that the complexities of managing change in practice reflect distinctive organizational environments and cultures. The skills and knowledge which managers found most useful were those that enabled them to "make sense" of the organizational change they subsequently experienced. The main impact of their earlier studies was to prompt informative, discursive and reflective approaches to change management. Practical implications - The paper discusses the implications for future teaching of organizational change and the development of organizational change theory. Originality/value - The qualitative findings of the study add to, and help to explain, earlier research findings on the questions of how managers' experience change, how they use organizational change theory and its impact on their practice. © Emerald Group Publishing Limited.

Clogging in subsurface-flow treatment wetlands:measurement, modeling and management

This paper reviews the state of the art in measuring, modeling, and managing clogging in subsurface-flow treatment wetlands. Methods for measuring in situ hydraulic conductivity in treatment wetlands are now available, which provide valuable insight into assessing and evaluating the extent of clogging. These results, paired with the information from more traditional approaches (e.g., tracer testing and composition of the clog matter) are being incorporated into the latest treatment wetland models. Recent finite element analysis models can now simulate clogging development in subsurface-flow treatment wetlands with reasonable accuracy. Various management strategies have been developed to extend the life of clogged treatment wetlands, including gravel excavation and/or washing, chemical treatment, and application of earthworms. These strategies are compared and available cost information is reported. © 2012 Elsevier Ltd.

Existence Results for Fractional Functional Differential Inclusions with Infinite Delay and Applications to Control Theory

Mathematics Subject Classification: 26A33, 34A60, 34K40, 93B05

Clogging in subsurface-flow treatment wetlands:occurrence and contributing factors

Clogging is a major operational and maintenance issue associated with the use of subsurface flow wetlands for wastewater treatment, and can ultimately limit the lifetime of the system. This review considers over two decades of accumulated knowledge regarding clogging in both vertical and horizontal subsurface flow treatment wetlands. The various physical, chemical and biological factors responsible for clogging are identified and discussed. The occurrence of clogging is placed into the context of various design and operational parameters such as wastewater characteristics, upstream treatment processes, intermittent or continuous operation, influent distribution, and media type. This information is then used to describe how clogging develops within, and subsequently impacts, common variants of subsurface flow treatment wetland typically used in the U.S., U.K., France and Germany. Comparison of these systems emphasized that both hydraulic loading rate and solids loading rate need to be considered when designing systems to operate robustly, i.e. hydraulic overloading makes horizontal-flow tertiary treatment systems in the U.K. more susceptible to clogging problems than vertical-flow primary treatment systems in France. Future research should focus on elucidating the underlying mechanisms of clogging as they relate to the design, operation, and maintenance of subsurface flow treatment wetlands. © 2010 Elsevier B.V.

Theory and practice in the field of foresight

Purpose – The paper aims to explore the gap between theory and practice in foresight and to give some suggestions on how to reduce it. Design/methodology/approach – Analysis of practical foresight activities and suggestions are based on a literature review, the author's own research and practice in the field of foresight and futures studies, and her participation in the work of a European project (COST A22). Findings – Two different types of practical foresight activities have developed. One of them, the practice of foresight of critical futures studies (FCFS) is an application of a theory of futures studies. The other, termed here as praxis foresight (PF), has no theoretical basis and responds directly to practical needs. At present a gap can be perceived between theory and practice. PF distinguishes itself from the practice and theory of FCFS and narrows the construction space of futures. Neither FCFS nor PF deals with content issues of the outer world. Reducing the gap depends on renewal of joint discourses and research about experience of different practical foresight activities and manageability of complex dynamics in foresight. Production and feedback of self-reflective and reflective foresight knowledge could improve theory and practice. Originality/value – Contemporary practical foresight activities are analysed and suggestions to reduce the gap are developed in the context of the linkage between theory and practice. This paper is thought provoking for futurists, foresight managers and university researchers.

An evaluation of coping ability as a guide to the treatment of persons diagnosed with schizophrenia and substance abuse

This dissertation introduced substance abuse to the Dynamic Vulnerability Formulation (DVF) and the social competence model to determine if the relationship between schizophrenic symptomatology and coping ability in the DVF applied also to the dually diagnosed schizophrenic or if these variables needed to be modified. It compared the coping abilities of dually and singly diagnosed clients in day treatment and identified, examined, and assessed the relative influence of relevant mediating variables on two dimensions of coping ability of the dually diagnosed: coping skills and coping effort. These variables were: presence of negative and nonnegative symptoms, duration of mental illness, type of substance used, and age of first substance use.^ A priori effect sizes based on previous empirical research were used to interpret the results related to the comparison of demographic, socioeconomic, and treatment characteristics between the singly and dually diagnosed study samples. The data suggested that the singly diagnosed group had higher coping skills than the dually diagnosed group, particularly in the areas of housing stability, work affect, and total social adjustment. The dually diagnosed group had lower scores on one aspect of coping effort--agency or self-efficacy. The data supported the presence of an inverse relationship between symptom severity and coping skills, particularly for the dually diagnosed group. The data did not support the presence of an inverse relationship between symptom severity and coping effort, but did suggest a positive relationship between symptom severity and one measure of coping effort, agency, for the dually diagnosed group. Regression equations using each summary measure of coping skill--social adjustment and role functioning--yielded statistically significant F-ratios. Thirty-six percent of the variance in social adjustment and thirty-one percent of the variance in role functioning were explained by the relative influence of the relevant variables. Both negative and non-negative symptoms were the only significant predictors of social adjustment. The non-negative symptoms variable was the sole significant predictor of role functioning. The results of this study provided partial support for the use of the Dynamic Vulnerability Formulation (DVF) with the dually diagnosed. ^

The non-linear acousto-mechanical and thermodynamic response of spherical absorbers to laser pulses of various temporal profiles

This study is to theoretically investigate shockwave and microbubble formation due to laser absorption by microparticles and nanoparticles. The initial motivation for this research was to understand the underlying physical mechanisms responsible for laser damage to the retina, as well as the predict threshold levels for damage for laser pulses with of progressively shorter durations. The strongest absorbers in the retina are micron size melanosomes, and their absorption of laser light causes them to accrue very high energy density. I theoretically investigate how this absorbed energy is transferred to the surrounding medium. For a wide range of conditions I calculate shockwave generation and bubble growth as a function of the three parameters; fluence, pulse duration and pulse shape. In order to develop a rigorous physical treatment, the governing equations for the behavior of an absorber and for the surrounding medium are derived. Shockwave theory is investigated and the conclusion is that a shock pressure explanation is likely to be the underlying physical cause of retinal damage at threshold fluences for sub-nanosecond pulses. The same effects are also expected for non-biological micro and nano absorbers. ^

Study of carbon nanotube film and shape memory alloys treatment for sensing and structural vibration control

Structural vibration control is of great importance. Current active and passive vibration control strategies usually employ individual elements to fulfill this task, such as viscoelastic patches for providing damping, transducers for picking up signals and actuators for inputting actuating forces. The goal of this dissertation work is to design, manufacture, investigate and apply a new type of multifunctional composite material for structural vibration control. This new composite, which is based on multi-walled carbon nanotube (MWCNT) film, is potentially to function as free layer damping treatment and strain sensor simultaneously. That is, the new material integrates the transducer and the damping patch into one element. The multifunctional composite was prepared by sandwiching the MWCNT film between two adhesive layers. Static sensing test indicated that the MWCNT film sensor resistance changes almost linearly with the applied load. Sensor sensitivity factors were comparable to those of the foil strain gauges. Dynamic test indicated that the MWCNT film sensor can outperform the foil strain gage in high frequency ranges. Temperature test indicated the MWCNT sensor had good temperature stability over the range of 237 K-363 K. The Young’s modulus and shear modulus of the MWCNT film composite were acquired by nanoindentation test and direct shear test, respectively. A free vibration damping test indicated that the MWCNT composite sensor can also provide good damping without adding excessive weight to the base structure. A new model for sandwich structural vibration control was then proposed. In this new configuration, a cantilever beam covered with MWCNT composite on top and one layer of shape memory alloy (SMA) on the bottom was used to illustrate this concept. The MWCNT composite simultaneously serves as free layer damping and strain sensor, and the SMA acts as actuator. Simple on-off controller was designed for controlling the temperature of the SMA so as to control the SMA recovery stress as input and the system stiffness. Both free and forced vibrations were analyzed. Simulation work showed that this new configuration for sandwich structural vibration control was successful especially for low frequency system.

The relationship of immigrant status to perceptions of reading and reading literacy among young Black students: A test of the Cultural -Ecological Theory of School Performance

This study tests Ogbu and Simons' Cultural-Ecological Theory of School Performance using data from the Progress in International Reading Literacy Study of 2001 (PIRLS), a large-scale international survey and reading assessment involving fourth grade students from 35 countries, including the United States. This theory argues that Black immigrant students outperform their non-immigrant counterparts, academically, and that achievement differences are attributed to stronger educational commitment in Black immigrant families. Four hypotheses are formulated to test this theory: Black immigrant students have (a) more receptive attitudes toward reading; (b) a more positive reading self-concept; and (c) a higher level of reading literacy. Furthermore, (d) the relationship of immigrant status to reading perceptions and literacy persists after including selected predictors. These hypotheses are tested separately for girls and boys, while also examining immigrant students' generational status (i.e., foreign-born or second-generation). ^ PIRLS data from a subset of Black students (N=525) in the larger U.S. sample of 3,763 are analyzed to test the hypotheses, using analysis of variance, correlation and multiple regression techniques. Findings reveal that hypotheses a and b are not confirmed (contradicting the Cultural-Ecological Theory) and c and d are partially supported (lending partial support to the theory). Specifically, immigrant and non-immigrant students did not differ in attitudes toward reading or reading self-concept; second-generation immigrant boys outperformed both non-immigrant and foreign-born immigrant boys in reading literacy, but no differences were found among girls; and, while being second-generation immigrant had a relatively stronger relationship to reading literacy for boys, among girls, selected socio-cultural predictors, number of books in the home and length of U.S. residence, had relatively stronger relationship to reading self-concept than did immigrant status. This study, therefore, indicates that future research employing the Cultural-Ecological Theory should: (a) take gender and generational status into account (b) identify additional socio-cultural predictors of Black children's academic perceptions and performance; and (c) continue to build on this body of evidence-based knowledge to better inform educational policy and school personnel in addressing needs of all children. ^

Workplace Discrimination Climate and Team Effectiveness: The Mediating Role of Collective Value Congruence, Team Cohesion, and Collective Affective Commitment

This study explored the relationship between workplace discrimination climate on team effectiveness through three serial mediators: collective value congruence, team cohesion, and collective affective commitment. As more individuals of marginalized groups diversify the workforce and as more organizations move toward team-based work (Cannon-Bowers & Bowers, 2010), it is imperative to understand how employees perceive their organization’s discriminatory climate as well as its effect on teams. An archival dataset consisting of 6,824 respondents was used, resulting in 332 work teams with five or more members in each. The data were collected as part of an employee climate survey administered in 2011 throughout the United States’ Department of Defense. The results revealed that the indirect effect through M1 (collective value congruence) and M2 (team cohesion) best accounted for the relationship between workplace discrimination climate (X) and team effectiveness (Y). Meaning, on average, teams that reported a greater climate for workplace discrimination also reported less collective value congruence with their organization (a1 = -1.07, p < .001). With less shared perceptions of value congruence, there is less team cohesion (d21 = .45, p < .001), and with less team cohesion there is less team effectiveness (b2 = .57, p < .001). In addition, because of theoretical overlap, this study makes the case for studying workplace discrimination under the broader construct of workplace aggression within the I/O psychology literature. Exploratory and confirmatory factor analysis found that workplace discrimination based on five types of marginalized groups: race/ethnicity, gender, religion, age, and disability was best explained by a three-factor model, including: career obstruction based on age and disability bias (CO), verbal aggression based on multiple types of bias (VA), and differential treatment based on racial/ethnic bias (DT). There was initial support to claim that workplace discrimination items covary not only based on type, but also based on form (i.e., nonviolent aggressive behaviors). Therefore, the form of workplace discrimination is just as important as the type when studying climate perceptions and team-level effects. Theoretical and organizational implications are also discussed.

Knowledge Protection in Firms : Theory and Evidence from HP Labs

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Radiotherapy Treatment Assessment using DCE-MRI

Abstract

The goal of modern radiotherapy is to precisely deliver a prescribed radiation dose to delineated target volumes that contain a significant amount of tumor cells while sparing the surrounding healthy tissues/organs. Precise delineation of treatment and avoidance volumes is the key for the precision radiation therapy. In recent years, considerable clinical and research efforts have been devoted to integrate MRI into radiotherapy workflow motivated by the superior soft tissue contrast and functional imaging possibility. Dynamic contrast-enhanced MRI (DCE-MRI) is a noninvasive technique that measures properties of tissue microvasculature. Its sensitivity to radiation-induced vascular pharmacokinetic (PK) changes has been preliminary demonstrated. In spite of its great potential, two major challenges have limited DCE-MRI’s clinical application in radiotherapy assessment: the technical limitations of accurate DCE-MRI imaging implementation and the need of novel DCE-MRI data analysis methods for richer functional heterogeneity information.

This study aims at improving current DCE-MRI techniques and developing new DCE-MRI analysis methods for particular radiotherapy assessment. Thus, the study is naturally divided into two parts. The first part focuses on DCE-MRI temporal resolution as one of the key DCE-MRI technical factors, and some improvements regarding DCE-MRI temporal resolution are proposed; the second part explores the potential value of image heterogeneity analysis and multiple PK model combination for therapeutic response assessment, and several novel DCE-MRI data analysis methods are developed.

I. Improvement of DCE-MRI temporal resolution. First, the feasibility of improving DCE-MRI temporal resolution via image undersampling was studied. Specifically, a novel MR image iterative reconstruction algorithm was studied for DCE-MRI reconstruction. This algorithm was built on the recently developed compress sensing (CS) theory. By utilizing a limited k-space acquisition with shorter imaging time, images can be reconstructed in an iterative fashion under the regularization of a newly proposed total generalized variation (TGV) penalty term. In the retrospective study of brain radiosurgery patient DCE-MRI scans under IRB-approval, the clinically obtained image data was selected as reference data, and the simulated accelerated k-space acquisition was generated via undersampling the reference image full k-space with designed sampling grids. Two undersampling strategies were proposed: 1) a radial multi-ray grid with a special angular distribution was adopted to sample each slice of the full k-space; 2) a Cartesian random sampling grid series with spatiotemporal constraints from adjacent frames was adopted to sample the dynamic k-space series at a slice location. Two sets of PK parameters’ maps were generated from the undersampled data and from the fully-sampled data, respectively. Multiple quantitative measurements and statistical studies were performed to evaluate the accuracy of PK maps generated from the undersampled data in reference to the PK maps generated from the fully-sampled data. Results showed that at a simulated acceleration factor of four, PK maps could be faithfully calculated from the DCE images that were reconstructed using undersampled data, and no statistically significant differences were found between the regional PK mean values from undersampled and fully-sampled data sets. DCE-MRI acceleration using the investigated image reconstruction method has been suggested as feasible and promising.

Second, for high temporal resolution DCE-MRI, a new PK model fitting method was developed to solve PK parameters for better calculation accuracy and efficiency. This method is based on a derivative-based deformation of the commonly used Tofts PK model, which is presented as an integrative expression. This method also includes an advanced Kolmogorov-Zurbenko (KZ) filter to remove the potential noise effect in data and solve the PK parameter as a linear problem in matrix format. In the computer simulation study, PK parameters representing typical intracranial values were selected as references to simulated DCE-MRI data for different temporal resolution and different data noise level. Results showed that at both high temporal resolutions (<1s) and clinically feasible temporal resolution (~5s), this new method was able to calculate PK parameters more accurate than the current calculation methods at clinically relevant noise levels; at high temporal resolutions, the calculation efficiency of this new method was superior to current methods in an order of 102. In a retrospective of clinical brain DCE-MRI scans, the PK maps derived from the proposed method were comparable with the results from current methods. Based on these results, it can be concluded that this new method can be used for accurate and efficient PK model fitting for high temporal resolution DCE-MRI.

II. Development of DCE-MRI analysis methods for therapeutic response assessment. This part aims at methodology developments in two approaches. The first one is to develop model-free analysis method for DCE-MRI functional heterogeneity evaluation. This approach is inspired by the rationale that radiotherapy-induced functional change could be heterogeneous across the treatment area. The first effort was spent on a translational investigation of classic fractal dimension theory for DCE-MRI therapeutic response assessment. In a small-animal anti-angiogenesis drug therapy experiment, the randomly assigned treatment/control groups received multiple fraction treatments with one pre-treatment and multiple post-treatment high spatiotemporal DCE-MRI scans. In the post-treatment scan two weeks after the start, the investigated Rényi dimensions of the classic PK rate constant map demonstrated significant differences between the treatment and the control groups; when Rényi dimensions were adopted for treatment/control group classification, the achieved accuracy was higher than the accuracy from using conventional PK parameter statistics. Following this pilot work, two novel texture analysis methods were proposed. First, a new technique called Gray Level Local Power Matrix (GLLPM) was developed. It intends to solve the lack of temporal information and poor calculation efficiency of the commonly used Gray Level Co-Occurrence Matrix (GLCOM) techniques. In the same small animal experiment, the dynamic curves of Haralick texture features derived from the GLLPM had an overall better performance than the corresponding curves derived from current GLCOM techniques in treatment/control separation and classification. The second developed method is dynamic Fractal Signature Dissimilarity (FSD) analysis. Inspired by the classic fractal dimension theory, this method measures the dynamics of tumor heterogeneity during the contrast agent uptake in a quantitative fashion on DCE images. In the small animal experiment mentioned before, the selected parameters from dynamic FSD analysis showed significant differences between treatment/control groups as early as after 1 treatment fraction; in contrast, metrics from conventional PK analysis showed significant differences only after 3 treatment fractions. When using dynamic FSD parameters, the treatment/control group classification after 1st treatment fraction was improved than using conventional PK statistics. These results suggest the promising application of this novel method for capturing early therapeutic response.

The second approach of developing novel DCE-MRI methods is to combine PK information from multiple PK models. Currently, the classic Tofts model or its alternative version has been widely adopted for DCE-MRI analysis as a gold-standard approach for therapeutic response assessment. Previously, a shutter-speed (SS) model was proposed to incorporate transcytolemmal water exchange effect into contrast agent concentration quantification. In spite of richer biological assumption, its application in therapeutic response assessment is limited. It might be intriguing to combine the information from the SS model and from the classic Tofts model to explore potential new biological information for treatment assessment. The feasibility of this idea was investigated in the same small animal experiment. The SS model was compared against the Tofts model for therapeutic response assessment using PK parameter regional mean value comparison. Based on the modeled transcytolemmal water exchange rate, a biological subvolume was proposed and was automatically identified using histogram analysis. Within the biological subvolume, the PK rate constant derived from the SS model were proved to be superior to the one from Tofts model in treatment/control separation and classification. Furthermore, novel biomarkers were designed to integrate PK rate constants from these two models. When being evaluated in the biological subvolume, this biomarker was able to reflect significant treatment/control difference in both post-treatment evaluation. These results confirm the potential value of SS model as well as its combination with Tofts model for therapeutic response assessment.

In summary, this study addressed two problems of DCE-MRI application in radiotherapy assessment. In the first part, a method of accelerating DCE-MRI acquisition for better temporal resolution was investigated, and a novel PK model fitting algorithm was proposed for high temporal resolution DCE-MRI. In the second part, two model-free texture analysis methods and a multiple-model analysis method were developed for DCE-MRI therapeutic response assessment. The presented works could benefit the future DCE-MRI routine clinical application in radiotherapy assessment.