Comparative analysis of imaging configurations and objectives for Fourier microscopy

Fourier microscopy is becoming an increasingly important tool for the analysis of optical nanostructures and quantum emitters. However, achieving quantitative Fourier space measurements requires a thorough understanding of the impact of aberrations introduced by optical microscopes, which have been optimized for conventional real-space imaging. Here, we present a detailed framework for analyzing the performance of microscope objectives for several common Fourier imaging configurations. To this end, we model objectives from Nikon, Olympus, and Zeiss using parameters that were inferred from patent literature and confirmed, where possible, by physical disassembly. We then examine the aberrations most relevant to Fourier microscopy, including the alignment tolerances of apodization factors for different objective classes, the effect of magnification on the modulation transfer function, and vignetting-induced reductions of the effective numerical aperture for wide-field measurements. Based on this analysis, we identify an optimal objective class and imaging configuration for Fourier microscopy. In addition, as a resource for future studies, the Zemax files for the objectives and setups used in this analysis have been made publicly available.Comment: For related figshare fileset with complete Zemax models of microscope objectives, tube lenses, and Fourier imaging configurations, see Ref. [41] (available at http://dx.doi.org/10.6084/m9.figshare.1481270

Wide-angle energy-momentum spectroscopy

Light emission is defined by its distribution in energy, momentum, and polarization. Here, we demonstrate a method that resolves these distributions by means of wide-angle energy-momentum spectroscopy. Specifically, we image the back focal plane of a microscope objective through a Wollaston prism to obtain polarized Fourier-space momentum distributions, and disperse these two-dimensional radiation patterns through an imaging spectrograph without an entrance slit. The resulting measurements represent a convolution of individual radiation patterns at adjacent wavelengths, which can be readily deconvolved using any well-defined basis for light emission. As an illustrative example, we use this technique with the multipole basis to quantify the intrinsic emission rates for electric and magnetic dipole transitions in europium-doped yttrium oxide (Eu$^{3+}$:Y$_{2}$O$_{3}$) and chromium-doped magnesium oxide (Cr$^{3+}$:MgO). Once extracted, these rates allow us to reconstruct the full, polarized, two-dimensional radiation patterns at each wavelength.Comment: 4 pages, 4 figure

An Analytical Study of It Security Governance and its Adoption on Australian Organisations

Contemporary organisations are at infancy stages of adopting IT governance processes in Australia. Organisations who have adopted these processes underestimate the security processes within the governance framework. If the security processes are designed, they are often flawed with operational level implementation. This study investigates IT security governance broadly and in Australian organisations specifically. The objective of this study is to bring the local organisations in alignment with international standards and frameworks in terms of integration of information security, IT audits, risks and control measures. A survey of selected organisations is completed and results are presented in this paper identifying the maturity level of IT security governance in Australian organisations against the well known Capability Maturity Model® (CMM.

Part I: Choreography Helen and Family Photo Part II: Movement and Story: An Exploration Through the Discourse of Dance

Artist Statement: My choreographic work is stimulated by a mental image that comes to me through research and observation of dance and other art forms. Once I have an image in my head then I realize the image by doing picture research. My image inspires a concept and characters that fit into the piece. I always plant my original image somewhere in the ending product of my dance. I choreograph by casting my dancers as characters. I use these characters to explore the essential relationships between people and the essential struggles we face as individuals. Creating personality based dances enables me to abstractly investigate theatrical situations. Sometimes I start rehearsal by having my dancers read a play out loud, as an easier way for them to grasp their character. Then I use text from the play to prompt movement phrases. Dance is an important outlet for me because I have been studying and exploring the art form since I was five years old. I believe that dance can express and convey any concept, realistic or abstract. A simple choreographic choice can make people think of many different things and can speak for itself. I choreograph to give the audience a chance to experience something different then their everyday lives and to allow them to engage their imagination

Development, Delivery and Dynamics of a Digital Forensics Subject

Digital forensics is a newly developed subject offered at Charles Sturt University (CSU). This subject serves as one of the core subjects for Master of Information Systems Security (Digital Forensics stream) course. The subject covers the legislative, regulatory, and technical aspects of digital forensics. The modules provide students detailed knowledge on digital forensics legislations, digital crime, forensics processes and procedures, data acquisition and validation, e-discovery tools, e-evidence collection and preservation, investigating operating systems and file systems, network forensics, email and web forensics, presenting reports and testimony as an expert witness. This paper summarises the process of subject development, delivery, assessments, teaching critique, and provides results from online subject evaluation survey. The dynamics and reflection on subject delivery is particularly important to determine if the subject has met its objectives. Results from the subject critique and student evaluation survey are presented and a reflection on how to improve the subject is provided

Study of the superconducting properties of the Bi-Ca-Sr-Cu-O system

High Temperature Superconductivity in the Bi-Ca-Sr-Cu-O System has been observed and has attracted considerable attention in 1988. The 80 K superconductivity phase has been identified to have a composition of Bi2CaSr2Cu2Ox, while the 110 K phase as reported in the literature has a possible composition of Bi2Ca2Sr2Cu3Ox. Researchers present here a study of the electrical properties of bulk samples of the slowly cooled and rapidly quenched 2:1:2:2 system. The samples used in this study were prepared from appropriate amounts of Bi2O3, CuO, SrCO3, CaCO3

Pathophysiological role of enhanced bone marrow adipogenesis in diabetic complications

Diabetes leads to complications in select organ systems primarily by disrupting the vasculature of the target organs. These complications include both micro-(cardiomyopathy, retinopathy, nephropathy, and neuropathy) and macro-(atherosclerosis) angiopathies. Bone marrow angiopathy is also evident in both experimental models of the disease as well as in human diabetes. In addition to vascular disruption, bone loss and increased marrow adiposity have become hallmarks of the diabetic bone phenotype. Emerging evidence now implicates enhanced marrow adipogenesis and changes to cellular makeup of the marrow in a novel mechanistic link between various secondary complications of diabetes. In this review, we explore the mechanisms of enhanced marrow adipogenesis in diabetes and the link between changes to marrow cellular composition, and disruption and depletion of reparative stem cells

An empirical study of challenges in managing the security in cloud computing

Cloud computing is being heralded as an important trend in information technology throughout the world. Benefits for business and IT include reducing costs and increasing productivity. The downside is that many organizations are moving swiftly to the cloud without making sure that the information they put in the cloud is secure. The purpose of this paper is to learn from IT and IT security practitioners in the Indian Continent the current state of cloud computing security in their organizations and the most significant changes anticipated by respondents as computing resources migrate from on-premise to the cloud. As organizations grapple with how to create a secure cloud computing environment, we believe the findings from this study can provide guidance on how to address business and technology risks exacerbated by cloud computing. Specifically, in this paper cloud computing users evaluate security technologies and control practices they believe are best deployed either onpremise or in the cloud. Survey results are presented where we have asked cloud-computing users to rate the types of sensitive or confidential information too risky to be moved to the cloud. Alongside this paper also discusses the need of having SSL in the cloud to provide definitive way of securing the cloud

Source code embedded (SCEM) security framework

Security in the Software Development Life Cycle (SDLC) has become imperative due to the variety of threats posed during and after system design. In this paper we have studied the security in system design in general and software development in particular, and have proposed strategies for integration of security in the SDLC. The paper highlights the needs of embedding security right from the earlier processes in the SDLC because patches and controls after the software delivery are more expensive to fix. We propose Source Code EMbedded (SCEM) security framework to improve the design of security policies and standards for the software development process to ensure the security and reliability in government departments such as taxation, auditing, national security, social security, and immigration. It is also envisaged that the implementation of SCEM security framework will ensure commercial and public trust in the software development process within Australia and worldwide, saving enormous redevelopment costs

Cellular Signaling and Potential New Treatment Targets in Diabetic Retinopathy

Dysfunction and death of microvascular cells and imbalance between the production and the degradation of extracellular matrix (ECM) proteins are a characteristic feature of diabetic retinopathy (DR). Glucose-induced biochemical alterations in the vascular endothelial cells may activate a cascade of signaling pathways leading to increased production of ECM proteins and cellular dysfunction/death. Chronic diabetes leads to the activation of a number of signaling proteins including protein kinase C, protein kinase B, and mitogen-activated protein kinases. These signaling cascades are activated in response to hyperglycemia-induced oxidative stress, polyol pathway, and advanced glycation end product formation among others. The aberrant signaling pathways ultimately lead to activation of transcription factors such as nuclear factor-κB and activating protein-1. The activity of these transcription factors is also regulated by epigenetic mechanisms through transcriptional coactivator p300. These complex signaling pathways may be involved in glucose-induced alterations of endothelial cell phenotype leading to the production of increased ECM proteins and vasoactive effector molecules causing functional and structural changes in the microvasculature. Understanding of such mechanistic pathways will help to develop future adjuvant therapies for diabetic retinopathy