Orbital angular momentum (OAM) is a property of light that is widely used for applications in bioimaging, optical communication and optical manipulation, but is mainly limited to the infrared and visible spectra. Developing a table-top source of Extreme Ultraviolet (XUV) light containing an arbitrary amount of OAM is yet to be achieved. We accomplish this by exploiting high-harmonic generation (HHG), a process whereby an infrared pump beam produces high order harmonics. We experimentally demonstrate the conservation of OAM in HHG by measuring harmonics of order n containing n times the OAM of the pump (n = 11, 13, 15 in our experiment). These results agree with our theoretical model. We also show theoretically how to manipulate the HHG process to impart an arbitrary amount of OAM to the di fferent harmonics. We hence show the way to a table-top and flexible source of XUV light containing orbital angular momentum.

This thesis asks the question: how can one describe the development of gated communities in Guatemala City? It collects and analyzes data on gated communities in Guatemala City in order to explore the nature of their development in a violent geographical region, which has also been neglected by the academic community. It argues that the development of gated communities in Guatemala City does not fit the mutually exclusive ‘security’ argument as scholars have made. Instead, a mixture of economic factors, social status, weak governance, and security concerns are involved as large private corporations draw upon security-related fears, unregulated development of real estate and weak governance, resulting in a disorganized model of spatial organization. This study adds to the growing body of literature on gated communities by laying the groundwork needed to fill the gap that currently exists in Central America.

The theory of electromagnetic characteristic modes was published roughly forty years ago, for both conducting and penetrable objects. However, while the characteristic mode analysis of conducting objects has found renewed interest as a tool for antenna designers, computed results for the characteristic mode eigenvalues, eigencurrents and eigenfields for penetrable objects have not appeared, not even in the seminal papers on the subject. In this thesis both volume and surface integral equation formulations are used to compute the characteristic modes of penetrable objects for what appears to be the first time. This opens the way for the use of characteristic mode theory in the design of antennas made of penetrable material whose polarization current densities constitute the main radiating mechanism of the antenna. Volume formulations are shown to be reliable but computationally burdensome. It is demonstrated that surface formulations are computationally more efficient, but obtrude some non-physical modes in addition to the physical ones. Fortunately, certain field orthogonality checklists can be used to provide a straightforward means of unambiguously selecting only the physical modes. The sub-structure characteristic mode concept is extended to problems involving both perfectly conducting and penetrable materials. It is also argued that sub-structure modes can be viewed as characteristic modes that implicitly use modified Green’s functions, but without such Green’s functions being needed explicitly. This makes the concept really practical, since the desired modified Green’s functions are not known explicitly in most cases.

Formation of lipid-laden macrophage foam cells and inflammation are the central components in the initiation and progression of atherosclerosis. ABCA1 is well established as an anti-atherogenic factor that facilitates cellular cholesterol and phospholipid efflux, promotes reverse cholesterol transport, and suppresses pro-inflammatory cytokine secretion. Through these functions, ABCA1 is capable of reducing the lipid burden in atherosclerotic plaque. PKA signaling is an integral factor in promoting many anti-atherogenic functions of ABCA1; however, mechanistic aspects of PKA signaling associated with ABCA1 remain poorly defined. Thus, the first part of this study investigates the involvement of spatially regulated PKA signaling in ABCA1 activities through the use of st-Ht31, a PKA de-anchoring peptide. It appears that de-anchoring PKA robustly increases ABCA1-mediated microparticle release, one of the cholesterol efflux pathways of ABCA1, and reverses macrophage foam cell formation. These results highlight the significance of subcellular compartmentalization of PKA signaling in ABCA1 functions and present PKA de-anchoring as a potential therapeutic strategy for atherosclerotic lesion regression. The second part of this study provides evidence that ABCA1 activates PKA and promotes the secretion of anti-inflammatory IL-10, a cytokine crucial for inflammation resolution. Furthermore, we provide evidence that this elevated PKA activity is the underlying mechanism in which macrophage ABCA1 promotes M2-like inflammatory response. Our results also suggest that ABCA1 activates PKA by regulating cholesterol, which poises macrophages towards an anti-inflammatory or M2-activated phenotype. Collectively, we demonstrate that PKA signaling plays a crucial multifactorial role in anti-atherogenic functions of ABCA1.

Duchenne Muscular Dystrophy (DMD) is an x-linked neuromuscular disease that is caused by an absence of dystrophin protein, rendering skeletal muscle more susceptible to contraction-induced damage. One therapeutic strategy focuses on increasing the expression of endogenous utrophin A, a dystrophin homologue. Interestingly, slow muscle is more resistant to the dystrophic pathology and has increased utrophin A expression (Webster 1998; Gramolini 2001b). These observations led researchers to explore the therapeutic potential of stimulating the slow, oxidative myogenic program (SOMP) in the mdx context. Beneficial adaptations were seen with pharmacological activation of PPARδ and AMPK. We treated mdx mice with resveratrol (~100mg/kg/day), a putative SIRT1 activator, for 6-7 weeks and evaluated the activity of phenotypic modifiers that are known to influence the SOMP. SIRT1 activity and protein levels increased significantly, as well as downstream PGC-1α activity. There was evidence of a fibre type conversion as the treated mice had a higher proportion of the slow myosin heavy chain isoforms in both the EDL and Soleus skeletal muscles. Utrophin A protein levels showed modest, but consistent increases with resveratrol treatment. Finally, histological analysis revealed improvements in central nucleation and fibre size variability. These findings were promising, but raised the question of whether modifying the treatment regimen may result in greater therapeutic benefits. Surprisingly, we discovered that an elevated dose of 500mg/kg/day was ineffective in its promotion of the SOMP. SIRT1 was not activated and there was no change in utrophin A levels with resveratrol treatment. Taken together, this study demonstrates that resveratrol has the ability to promote the SOMP through SIRT1 and PGC-1α activation. It also highlights the importance of selecting an appropriate dose of resveratrol to maximize its effectiveness.

Studies on the career paths of municipal police officers have revealed an emergence of four distinct phases which officers pass through during their professional careers, phases where the perception of their profession changes. These phases are more constant at the patrol officer level where most officers begin and finish their career. Among these four phases is the disillusion phase (between 6 and 13 years), where the expectations at work are not met. The perception of the police administration, the public and the criminal justice system, all become negative and the hope for promotions diminish. These studies were mainly conducted in a period where there were very few or no women in policing. Through a feminist perspective and a social constructionist theoretical framework, this thesis makes the hypothesis that because women have different expectations at work, a varying work/life balance and a contrasting aspiration to attain positions of power, women will live this second phase differently. To explore this hypothesis, data was collected from ten semi-structured interviews with female patrol officers having worked between 6 and 13 years in municipal police departments. A discourse analysis effectively shows significant differences for the reasons underlying our hypotheses. Even if they have some frustrations about certain aspects of their work, we did not see any disillusionment from any women in this phase.

This study contends that the spaces where crime occurs in films are not neutral; they are layered with maps of meaning that we construct somewhere between the imagined and the lived. Given that popular cultural representations both shape and reflect our understandings of crime and space, a study examining where crime occurs in films was warranted but previously unrealized in the criminological literature. This study addresses this gap in the literature by considering how geographies of crime are characterized in a sample of ten recent popular crime films. Applying a qualitative content analysis approach, this study foregrounds the onscreen spaces where crimes occur in an attempt to expose and denaturalize the meanings around crime that are embedded in these backgrounds. Particular regard is given here to the twinning of crime and urbanity, the aesthetics of insecurity, and the gendering of geographies of crime.

Organizations in many domains such as healthcare, finances, telecommunications, educa-tion, and software development, must comply with an ever-increasing number of regula-tions, including laws and policies. In order to measure compliance to regulation, several recent approaches propose modelling regulations using goals and indicators. However, creating goal models for regulations is time consuming and prone to errors, especially as this is usually done manually. This thesis tackles this issue by automating some of the steps for creating goal models, and by offering better ways to create graphical views of goal models than what is currently available nowadays in goal modelling tools. The notation used in this thesis is the Goal-oriented Requirement Language (GRL), which is part of the User Requirements Notation standard and is supported by the jUCMNav tool. The concepts of regulations and their indicators are captured using a tab-ular presentation in Comma-Separated Value (CSV) files. An import mechanism is added to jUCMNav to automatically create regulation goal models from such files. The imported GRL model can then by visualized using novel features that enable the addition of multiple views/diagrams in an efficient and usable way.

Wavelength reuse techniques for bidirectional ultra-wide band (UWB) over fiber (UWBoF) networks are presented. The downstream optical signal from the central station (CS) is reused for upstream data transmission with the original data erased at the base station (BS). Two wavelength reuse schemes for the generation of a clear optical carrier at the BS are theoretically analyzed and experimentally demonstrated. In the first scheme, the wavelength reuse is based on phase-modulation to intensity-modulation (PM-IM) conversion and destructive interferencing using a polarization modulator (PolM) and a fiber Bragg grating (FBG). A theoretical analysis is performed which is verified by an experiment. In the second scheme, the wavelength reuse is based on injection locking of a Fabry–Pérot laser diode (FP-LD) and polarization multiplexing. The UWB injection signal contributes to better BERs of both downstream and upstream services and a lower power penalty cause by the wavelength reuse of the whole system than the baseband signal. A bidirectional point-to-point transmission of over a 25-km single-mode fiber (SMF) using a single wavelength from the CS in each scheme is demonstrated.

While the role of the school principal has received much attention in stable environments, little research exists on principals working in conflict-affected countries. The purpose of this phenomenological study is to uncover perceptions of Somali principals in Mogadishu regarding their roles and lived experiences, as well as the challenges they face as they lead their schools amid ongoing conflict. In order to understand the different dimensions of the principal’s role and how this role is experienced in such a context, a descriptive phenomenology has been employed. A purposeful sample of eight primary school principals in Mogadishu, which has been the epicentre of the ongoing conflict, was indentified and the principals were interviewed. Through the six-step approach to phenomenological data analysis, as suggested by Creswell (2013), 11 themes were identified. Findings revealed that principals perceived their role as supporting teachers personally and professionally, supervising instruction, facilitating teacher professional development when the security situation permits, having good relationships with governing bodies, and building community collaboration. Findings also showed that, besides security concerns, student mobility, poor facilities, shortage of trained teachers and student discipline were the major challenges to principals. Findings further indicated that principals acted as boundary spanners using a variety of buffering and bridging strategies in an attempt to minimize uncertainty and security risks, as well as to adapt the school to the volatile environment. Furthermore, commitment to keep schools open, despite the huge challenges, a sense of responsibility for student safety, and calm and courageous actions in the face of danger were perceived as critical factors in sustaining principals in their positions. Four conclusions were drawn from the study, including principals’ lack of unity in the perception of their roles, principals’ lack of pre-service training, the possibility and essentiality of providing education during armed conflicts, and the importance of creating strong bonds through principals’ supportive roles. Recommendations were offered for primary principals, local educational umbrellas, NGOs, and UN agencies, as well as for further research possibilities.