Developing a Tip-Enhanced Fluorescence Microscope for Applications in Super-Resolution and Correlative Imaging

This thesis describes the development of a tip-enhanced fluorescence microscope, based upon combining confocal fluorescence methods with a commercially-available atomic force microscope (AFM). A microscope which is capable of simultaneous fluorescence and atomic force measurements has been realised. This has been achieved by mounting an AFM onto an inverted optical microscope, allowing the sample to be fluorescently excited from underneath. The incident position of the excitation spot at the sample can be controlled by a 2D galvanometer present in the excitation beam path. A program has been developed which aligns the laser spot with the AFM-tip by correlating sample features, and then applying a corresponding voltage to the galvanometer, in order to translate the beam towards the AFM-tip. A result of this process is that the fields-of-view of the fluorescence and atomic force images are also aligned, enabling simultaneous correlative microscopy. The benefits of performing these techniques simultaneously include eliminating the need to image over large areas with both techniques to ensure overlapping fields-of-view (as would be required if these measurements were being performed consecutively). It also unlocks the potential to track the mechanical changes of a known structure over time. Moreover, elements of the alignment program may be useful for general applications in correlative microscopy, providing an automated tool for overlaying images which have been obtained using different techniques. Alongside simultaneous imaging, this alignment method is also a potential technique for introducing a tip-enhancement effect into this particular instrument. A method has been developed which acquires data from a single photon counting module (SPCM) and the AFM using a LabVIEW field programmable gate array (FPGA), and subsequently correlates the number of detected photons from the sample with the position of the AFM-tip at that time. Although fluorescence enhancement was not detected using this instrument, the method was sufficient enough to detect scatter as the AFM-tip made contact with the sample; this is evidence that the method can successfully measure the number of photons detected with respect to tip-sample separation and should be able to also detect an increase in photons due to enhancement, if the effect can be optimised

Maternal mortality in Australia: Learning from maternal cardiac arrest

Cardiac arrest in pregnancy is fortunately a rare event that few midwives will see during their career. The increase in maternal age, the Body Mass Index, cesarean sections, multiple pregnancies, and comorbidities over recent years have increased the probability of cardiac arrest. The early warning signs of impending maternal cardiac arrest are either absent or go unrecognized. Maternal mortality reviews highlight the deficiencies that maternity care providers have in managing cardiac arrest in pregnancy. The aim of this article is to address the knowledge deficiencies of health professionals by reviewing the physiological changes in pregnant women that complicate the management of cardiopulmonary resuscitation, using a case scenario. There are key differences in the management of pregnant women, when compared to standard adult resuscitation. The outcome is dependent on the speed of the response and the consideration of a number of crucial pregnancy-specific interventions. Staff members need to be adequately trained in order to deal with maternal cardiac arrest and have access to training packages and in-service education programs. As cardiac arrest in pregnancy is a rare event, emergency drill simulations are an important component of ongoing education. © 2011 Blackwell Publishing Asia Pty Ltd.

Education, employment and practice: Midwifery graduates in Papua New Guinea

© 2016 The Authors Background Papua New Guinea has a very high maternal mortality rate (773/100,000), low rates of supervised births and a critical shortage of skilled midwives. A midwifery education initiative commenced in 2012, funded by the Australian Government and led by the National Department of Health. One specific objective of the initiative was to improve the standard of clinical teaching and practice in four schools of midwifery. There were 394 midwives educated over the 4 year period (2012–2015) representing half of all midwives in Papua New Guinea. A study was undertaken to describe the educational programme, employment, practices and experiences of graduates who studied midwifery in 2012 and 2013 as part of the initiative. Objective the aim of this paper is to explore the education, employment and practice of newly graduated midwives in Papua New Guinea. Design a mixed methods descriptive study design was used. Surveys and focus groups were used to gather data. Ethical approval was granted by the relevant Human Research Ethics Committees. Setting and participants all midwifery graduates in 2012 and 2013 from the four midwifery schools in Papua New Guinea were included in the study and almost 80% were contacted. Findings nearly 90% of graduates were working as midwives, with an additional 3% working as midwifery or nursing educators. This study discovered that graduates exhibited increased skills acquisition and confidence, leadership in maternal and newborn care services and a marked improvement in the provision of respectful care to women. The graduates faced challenges to implement evidence based care with barriers including the lack of appropriate resources and differences of opinion with senior staff. Conclusions factors affecting the quality of midwifery education will need to be addressed if Papua New Guinea is to continue to improve the status of maternal and newborn health. Specifically, the length of the midwifery education, the quality of clinical practice and the exposure to rural and remote area practice need addressing in many contexts like Papua New Guinea

The architectures of media power: editing, the newsroom, and urban public space

This paper considers the relation of the newsroom and the city as a lens into the more general relation of production spaces and mediated publics. Leading theoretically from Lee and LiPuma’s (2002) notion of ‘cultures of circulation’, and drawing on an ethnography of the Toronto Star, the paper focuses on how media forms circulate and are enacted through particular practices and material settings. With its attention to the urban milieus and orientations of media organizations, this paper exhibits both affinities with but also differences to current interests in the urban architectures of media, which describe and theorize how media get ‘built into’ the urban experience more generally. In looking at editing practices situated in the newsroom, an emphasis is placed on the phenomenological appearance of media forms both as objects for material assembly as well as more abstracted subjects of reflexivity, anticipation and purposiveness. Although this is explored with detailed attention to the settings of the newsroom and the city, the paper seeks to also provide insight into the more general question of how publicness is material shaped and sited

S-, P- and D-wave resonances in positronium-sodium and positronium-potassium scattering

Scattering of positronium (Ps) by sodium and potassium atoms has been investigated employing a three-Ps-state coupled-channel model with Ps(1s,2s,2p) states using a time-reversal-symmetric regularized electron-exchange model potential fitted to reproduce accurate theoretical results for PsNa and PsK binding energies. We find a narrow S-wave singlet resonance at 4.58 eV of width 0.002 eV in the Ps-Na system and at 4.77 eV of width 0.003 eV in the Ps-K system. Singlet P-wave resonances in both systems are found at 5.07 eV of width 0.3 eV. Singlet D-wave structures are found at 5.3 eV in both systems. We also report results for elastic and Ps-excitation cross sections for Ps scattering by Na and K.Comment: 9 pages, 5 figures, Accepted in Journal of Physics

Solitary waves of nonlinear nonintegrable equations

Our goal is to find closed form analytic expressions for the solitary waves of nonlinear nonintegrable partial differential equations. The suitable methods, which can only be nonperturbative, are classified in two classes. In the first class, which includes the well known so-called truncation methods, one \textit{a priori} assumes a given class of expressions (polynomials, etc) for the unknown solution; the involved work can easily be done by hand but all solutions outside the given class are surely missed. In the second class, instead of searching an expression for the solution, one builds an intermediate, equivalent information, namely the \textit{first order} autonomous ODE satisfied by the solitary wave; in principle, no solution can be missed, but the involved work requires computer algebra. We present the application to the cubic and quintic complex one-dimensional Ginzburg-Landau equations, and to the Kuramoto-Sivashinsky equation.Comment: 28 pages, chapter in book "Dissipative solitons", ed. Akhmediev, to appea

Celebrity advocacy and public engagement: the divergent uses of celebrity

This article sounds a cautionary note about the instrumental use of celebrity advocacy to (re)engage audiences in public life. It begins by setting out the steps necessary to achieve public recognition of a social problem requiring a response. It then presents empirical evidence which suggests that those most interested in celebrity, while also paying attention to the main stories of the day, are also least likely to participate in any form of politics. However, this does not rule out the possibility of forging a link between celebrity and public engagement, raising questions about what would potentially sustain such an articulation. After discussing the broader cultural context of celebrity advocacy in which perceived authenticity functions valorised form of symbolic capital, the article outlines a phenomenological approach to understanding the uses audiences make of celebrity advocacy, using the example of a Ewan McGregor UNICEF appeal for illustration. It concludes that while media encounters with celebrities can underpin a viewer’s sense of self, this is as likely to lead to the rationalisation of inaction as a positive response to a charity appeal

Discovery of the Acoustic Faraday Effect in Superfluid 3He-B

We report the discovery of the acoustic Faraday effect in superfluid 3He-B. The observation of this effect provides the first direct evidence for propagating transverse acoustic waves in liquid 3He, a mode first predicted by Landau in 1957. The Faraday rotation is large and observable because of spontaneously broken spin-orbit symmetry in 3He-B. We compare the experimental observations with a simulation of the transverse acoustic impedance that includes the field-induced circular birefringence of transverse waves.Comment: 4 pages in RevTex plus 3 postscript figures; new version includes: minor corrections to the text and an updated of list of reference