Accurate detection and segmentation of intracranial aneurysms plays an important role in diagnosing and reducing the incidence of subarachnoid haemorrhage (SAH) which is associated with high rates of morbidity and mortality. This research proposes a computer aided detection (CAD) and segmentation (CAS) of intracranial aneurysm in computer tomography angiography (CTA). The efficiency of the CAD/CAS system is boosted by pre-processing the input image with non-linear diffusion to smooth the CTA data while preserving the edges. A 3D region growing-based approach is used to extract the cerebral arteries followed by entropy-based search space reduction to retain the volume of the circle of Willis (CoW) and the proximal cerebral arteries where nearly all intracranial aneurysms are located, whilst eliminating the extracranial and very distal intracranial circulation. Because cerebral aneurysms vary in size we regard the problem of cerebral aneurysm detection as an intrinsically multi-scale problem and employ a multi-scale approach to all detection analysis. Shape index analysis is employed to determine potential aneurysmal regions (PARs). Hessian analysis and gradient vector field analysis which reveal 3D local shape information are used to further characterise the initial PARs. False positive reduction is then performed based on the analysis of the shape characterisations of the PARs. A ranking score is defined based on the outcomes of the shape analysis to rank the likelihood of PARs. The system allows user to navigate through the ranked PARs and select a candidate aneurysm for further analysis (CAS). The boundary of the selected aneurysm and its parent artery is delineated by using a 3D conditional morphology-based region growing approach. The output is presented to the user to be assessed for the aneurysm orientation relative to the parent vessel. A semi-automatic process is applied to detach the aneurysm from its parent artery. To have a fine segmentation of aneurysm which can be used for characterization of the aneurysm, a 3D geodesic active contour implemented in a level set framework is applied. The volume of the separated aneurysm is quantified as a typical characterization ofthe aneurysm. The system has been validated on a clinical dataset of 62 CT A scans with average 274 slices per scan (involving 17,028 CT slices) containing 70 aneurysms. Sizes of aneurysms vary between 3-16mm. 42 CTA scans have been used as a training dataset for parameter selection and 20 CTA scans have been used as a test dataset. The sensitivity of the systems for the CAD component is 97% with the average false positive of 2.24 per dataset (0.008 per slice). CAS performance was evaluated by dual visual judgment of an expert neuroradiologist and neurosurgeon. The detection and segmentation performance indicate the approach has potential in clinical applications.

Interruptions research is heavily reliant on a paradigm involving 'enforced interruption'. Email use however constitutes a special form of 'controlled interruption'. Because people have control over when and how they respond to incoming email, email interruptions provide an excellent tool for exploring strategic behaviour at work. This thesis uses the goal-directed theories of Action Regulation Theory (ART: Hacker, 1985; 1994) and Hockey's (1997, 2000, 2002) cognitive-energetical compensatory control model to frame research into strategic behaviour across three research phases. Using a multimethodological and multi-analysis approach, and in common with recommendations from the goal-directed theories, the experiences of 134 real email users, executing real strategies for dealing with email interruptions were examined within their authentic work environments. Semi-structured interviews and diary methodology, using content analysis and multilevel random coefficient modelling (MRCM), revealed that: Wellbeing is both an antecedent and consequence of strategic behaviour in dealing with email interruptions. Individual differences - measured using structured, taxonomical personality and motivational style inventories - are directly linked to strategy choice, consequential wellbeing, and the prioritisation of different goals at work, when dealing with email interruptions. They also moderate the relationship between strategy choice and wellbeing. In multi-goal enVironments, people's strategies for dealing with email interruptions depend in part on how they prioritise the email against the task (in a stage labelled the negotiation lag), and whether this relates to decisions to satisfy their current task goals, other work goals and wellbeing goals. In satisfying one goal (e.g., a work goal) this doesn't necessarily mean that other goals (e.g., for wellbeing) will suffer. This thesis asserts that such findings are novel and unique, and that they address shortcomings in the goal-directed theories, and in the way that interruptions have been studied to date. Implications for theory and practice are highlighted.

An integrated security framework is proposed for detecting enterprise-wide network attacks. The proposed framework defines three types of components, namely, sensor, analysis and response. Sensor components gather evidence about security attacks. Analysis components correlate and combine pieces of attack evidence gathered by sensors, in order to detect attacks perceived on the network. Response components execute recommended responses and can be configured to assist humans in executing security countermeasures. Both schematic and formal descriptions of the framework and its components are provided and discussed. General and specific requirements of each component are outlined. To integrate components of the framework together, a lightweight signalling mechanism referred to as "security spaces" is proposed. A security space is a type of "tuple space" that allows sensor, analysis and response components to connect, contribute and communicate security related information. Its application to distributed sensor, and federated sensor environments is described. The detection of enterprise-wide attacks targeting computer networks is accomplished by distributing sensors across the network to collate evidence of perceived attacks, which are communicated to the analysis component for further investigation. In the analysis, a novel approach in data fusion is applied. This approach is underpinned by the Dempster-Shafer theory of evidence that is utilised to collectively combine pieces of attack evidence gathered by the sensors. The fusion of sensor evidence assists to provide accurate detection of attacks perceived on the entire network. Further, to assist security administrators to visualise and mitigate perceived attacks, graph theory and graph matching algorithms are employed in the analysis. Hence, a graph model - pattern activity graph - is proposed and investigated in representing security attacks perceived on the network. Both graph isomorphism and subgraph iso-morphism are used to compare attack graph templates to data graphs obtained from security events. To validate the objectives of this research, a series of experiments were conducted on a testbed network, where live network traffic was monitored. A dataset comprising background data and attack data was gathered. Background data is normal data obtained by monitoring the testbed network. Attack data was generated through the attacks conducted on the monitored testbed LAN. The attacks were primarily network scans, network worms, web attacks, policy violations, and stealthy network scans attacks.

<p> This study is an examination of how ethnicity and religion affect political behavior of Kurds of Turkey. Despite the presence of some predisposing factors (violent conflict, high ethnic polarization, and significant population size), a substantial portion of Kurds prefer non-ethnic political parties (specifically the ruling Islamist party, the Justice and Development Party) to the pro-Kurdish political parties that have struggled for certain ethnic political and cultural rights. This dissertation systematically and comparatively investigates the ethnicity-based demands (political and cultural) and ethnic identity perceptions of the Kurds who subscribe to either ethnic or non-ethnic political parties. To this end, I have developed a model based on a significant conceptual distinction, derived from the relevant literature, between ethnic category and ethnic group. I demonstrate that membership in the Kurdish ethnic category does not necessarily imply membership in the Kurdish ethnic groups constructed and led by Kurdish political entrepreneurs. More specifically, my argument in this study is two-fold: First, while Kurds generally support ethnic cultural demands, they differ significantly in terms of their political demands. That is, while the overwhelming majority of those who support the pro-Kurdish political parties constitute the Kurdish ethnic groups by sharing the political demands raised by their ethnic entrepreneurs, the majority of those who support non-ethnic political parties do not support these political demands. Second, I argue that there are two forms of Kurdish ethnic identity perception in relation to Islam: secular and non-secular/religious. The Kurds who support the pro-Kurdish political parties as ethnic political groups are more likely to adopt a secular form of Kurdish identity that has been constructed and promoted by the Kurdish political elites, while those Kurds who support the ruling Islamist party (JDP/AKP) are more likely to display a non-secular form of Kurdish identity. </p><p>

<p> National parks and protected areas are an integral component of the Mexican government&rsquo;s long-term natural resource conservation strategy. They comprise over 90 million hectares throughout the country. However, the establishment and upkeep of these protected areas often incites conflict both between and among local actors. From poachers taking protected resources to indigenous peoples exercising their rights, protected areas have become a source of political, economic, and moral contention across the globe. In addition, their effectiveness in either ecological or sustainable development terms has been ambiguous at best. </p><p> Tulum, Mexico exemplifies this dilemma. The site of pre-Columbian Mayan architecture, Tulum is now facing explosive economic growth driven largely by an international tourism industry. This fragile ecological site and vulnerable cultural community have the potential to be seriously impacted by mass tourism. Accompanying the myriad social, political and ecologic implications of tourism are real challenges for park managers, who are placed in the delicate position of attending to federal objectives while mitigating on the ground realities. </p><p> This report chronicles nearly two months of ethnographic field work conducted with The National Commission for Natural Protected Areas, a federal government agency responsible for the management and administration of protected areas in Mexico. Preliminary results suggest that effective management strategies of protected areas are constrained due to &ldquo;top down&rdquo; and hierarchical management philosophies and approaches that do not adequately incorporate the multiple challenges faced by local communities, especially in light of the burgeoning tourism pressures. This report recommends the implementation of a participatory applied ecological management framework that adequately includes perspective from local actors. Hopefully, Tulum can come to represent a locality in which internationally-based tourism development can coexist with an increasing capacity for the adaptive management of natural protected areas.</p><p>

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2009. / Source: Dissertation Abstracts International, Volume: 70-06, Section: A, page: . Adviser: Carol Leff. Includes bibliographical references (leaves 190-203) Available on microfilm from Pro Quest Information and Learning.

This study aims to understand the use of a computer during GP consultations and to enable the development of EPR systems which are easier to review, enter data into, use to take action, and is more sensitive to the clinical context. This thesis reports the development of a multi-channel video and data capture toolkit, the ALFA (Activity Log File Aggregation) because existing observation techniques have limitations. None of the existing tools are designed to assess human-computer interaction in the context of the clinical consultation, where the social interaction is the prime focus. The ALFA tool-kit has been used to observe and study 163 live primary care consultations supported by computer systems with four different designs. A detailed analysis of consultation interactions was then performed focusing on doctor-patient communication and the integration of the computer into the consultation workflow. The data collection elements of the ALFA supported recording of consultation activities by providing rating techniques attuned with the characteristics of those interactions. The Log File Aggregation (LFA) component of the ALFA toolkit aggregated those multitudes of data files into a single navigable output that can be studied both quantitatively and qualitatively. A set of Unified Modelling Language (UML) sequence diagrams were then created as they could be used by software engineers to develop better systems. This research proposes a framework with three elements to analyse the computerised clinical consultation; (1) the overview of the context within which the consultation was carried out, (2) time taken to perform key consultation tasks and (3) the process used. Traditional analysis with its emphasis on the technology often misses crucial features of the complex work environments in which the technology is implemented. Direct observation could inform software designers in developing systems that are more readily integrated into clinical workflow. Direct observation of the consultation, using the ALFA toolkit is acceptable to patients; captures the context of the consultation the precise timing and duration of key tasks; and produces an output a software engineer can understand. ALFA offers a range of possibilities for research in the consulting room. The computer should be considered as an active element of the consultation; room layout and consultation models should let the computer in, while software engineers take in the capacity to sustain patient centred social interactions as a core facet of their design agenda.

Pulmonary embolism (PE) is an obstruction within the pulmonary arterial tree and in the majority of cases arises from a thrombosis that has travelled to the lungs via the venous system. Pulmonary embolism (PE) is a fatal condition which affects all age groups and is the third most common cause of death in the US. Computed tomographic angiography (CTA) imaging has recently emerged as an accurate method in the diagnosis of pulmonary embolism. Each CTA scan contains hundreds of CT images, so the accuracy and efficiency of interpreting such a large image data set is complicated due to various PE look-alikes and human factors such as attention span and eye fatigue. Moreover, manual reading and interpreting a large number of slices is time consuming and it is difficult to find all the pulmonary embolisms (PE) in a data set. Consequently, it is highly desirable to have a computer aided detection (CAD) system to assist radiologists in detecting and characterizing emboli in an accurate, efficient and reproducible manner. A computer aided detection (CAD) system for detection of pulmonary embolism is proposed in CTA images. Our approach is performed in three stages: firstly the pulmonary artery tree is extracted in the region of the lung and heart in order to reduce the search area (PE occurs inside the pulmonary artery) and aims to reduce the false detection rate. The pulmonary artery is separated from the surrounding organs by analyzing the second derivative of the Hessian matrix and then a hybrid method based on region growing and a new customized level set is used to extract the pulmonary artery (PA). In the level set implementation algorithm, a new stopping criterion is applied, a consideration often neglected in many level set implementations. In the second stage, pulmonary embolism candidates are detected inside the segmented pulmonary artery, by an analysis of three dimensional features inside the segmented artery. PE detection in the pulmonary artery is implemented using five detectors. Each detector responds to different properties of PE. In the third stage, filtering is used to exclude false positive detections associated with the partial volume effect on the artery boundary, flow void, lymphoid tissue, noise and motion artifacts. Soft tissue between the bronchial wall and the pulmonary artery is a common cause of false positive detection in CAD systems. A new feature, based on location is used to reduce false positives caused by soft tissue. The method was tested on 55 data scans (20 training data scans and 35 additional data scans for evaluation containing a total of 195 emboli). The system provided a segmentation of the PA up to the 6th division, which includes the sub-segmental level. Resulting performance gave 94% detection sensitivity with an average 4.1 false positive detections per scan. We demonstrated that the proposed CAD system can improve the performance of a radiologist, detecting 19 (11 %) extra PE which were not annotated by the radiologist.

<p> Long-term precipitation, temperature, and streamflow records were used to compare changes in precipitation and potential evapotranspiration to changes in runoff within 25 stream basins. Historical changes in the region appear to be more consistent with complex transient shifts in seasonal climatic conditions than with gradual climate change. Annual peak streamflow data were divided into two populations, snowmelt/spring and summer/fall, to test the hypotheses that, because of changes in precipitation regimes, the odds of summer/fall peaks have increased and, because of temperature changes, snowmelt/spring peaks happen earlier. The odds of summer/fall peaks occurring have increased across the study area. In northern portions of the study region, snowmelt/spring peaks are occurring earlier by 8.7 to 14.3 days. Tree-ring chronologies and historical precipitation data in a region around the Souris River Basin, were analyzed to model past long-term variations of precipitation. Results show that precipitation varies on multi-decadal time scales. </p><p> The Red River of the North drains much of eastern North Dakota and northwestern Minnesota and flows north into Manitoba, Canada, ultimately into Lake Winnipeg, so phosphorus transport is an International concern. Phosphorus changes over time were determined and phosphorus concentrations at the International border, when adjusted for variability in streamflow (flow-normalized), have generally increased from 1972-2012; however, most of that increase happened in the 1970s. Flux, the total amount of phosphorus transported, has increased dramatically in recent decades; however, when adjusted for streamflow variability (so that flux is from variation caused by the occurrence of high- or low-flow conditions), the flow-normalized flux has declined in recent years. This indicates that an important reason for increased flux is climatic &ndash; the wet conditions experienced since 1993. </p><p> These changes have implications for water interests, such as potential changes in lead-time for flood forecasting or changes in the operation of flood-control dams or wastewater treatment plants. Results suggest that the recent wet period may be a part of natural variability on a very long time scale and that this not only has implications for flood risk, but for nutrient export to Canada.</p>

<p> This dissertation includes three essays that present a quantitative analysis of the policy implications of gender equality and religious attitudes as predictors of terrorism at the state level using a broad dataset. Essay one focuses on impact of gender equality, especially women's political empowerment on terrorism, both domestic and transnational. The second essay examines both gender equality attitudes and actual outcomes in social, economic and political spheres, to measure their effect on terrorism. The third essay analyzes the relation of religiousness in a society with incidents and lethality of terrorism. The overall findings of this thesis suggest that attitudes and norms of gender equality matter with regard to terrorism, but practices and outcomes matter more. Results also indicate that religious attitudes of a society are associated with lethality of terror attack. These findings have important policy implications for rethinking prevention of terrorism in an effective and innovative manner. The results strongly support investment in women's rights programs, promotion of religious tolerance and provision of social services as indirect policy solutions to curb the conditions that foster terrorism.</p>