6,665 research outputs found
Multimode analysis of the light emitted from a pulsed optical parametric oscillator
We present a multimode treatment of the optical parametric oscillator, which
is valid for both pulsed and continuous-wave pump fields. The two-time
correlation functions of the output field are derived, and we apply the theory
to analyze a scheme for heralded production of non-classical field states that
may be subsequently stored in an atomic quantum memory.Comment: 11 pages, 6 figure
Fluorescence visualization of a convective instability which modulates the spreading of volatile surface films
The spontaneous spreading of a thin liquid film along the surface of a deep liquid layer of higher surface tension is a ubiquitous process which provides rapid and efficient surface transport of organic or biological material. For a source of constant concentration, the leading edge of a nonvolatile, immiscible film driven to spread by gradients in surface tension is known to advance as t^3/4 in time. Recent experiments using laser shadowgraphy to detect the advancing front of spreading films indicate, however, that immiscible but volatile sources of constant concentration spread with a reduced exponent according to t^1/2. Using a novel technique whereby fluorescent lines are inscribed in water, we have detected the evolution of a thermal instability beneath the leading edge of volatile films which strongly resembles a Rayleigh-BĂŠnard roll. We propose that the increased dissipation from this rotational flow structure is likely responsible for the reduction in spreading exponent. This observation suggests a conceptual framework for coupling the effects of evaporation to the dynamics of spreading
Addressing English language proficiency in a business faculty
In the Faculty of Business and Law at Edith Cowan University, the percentage of international students enrolling in both undergraduate and postgraduate courses is increasing rapidly. The vast majority of these students come from backgrounds where English is not their main language of communication and a number come from regions where English is barely spoken. In order to assist these students in the most effective manner, at the beginning of first semester in 2009, the Faculty initiated the Business Literacy and Numeracy Project. This paper delves into the literacy aspect of this project. It charts why such a project was established, outlines various actions taken, and proposes some likely outcomes
Stellar Clusters in NGC 1313: Evidence for Infant Mortality
We present evidence that infant mortality of stellar clusters is likely to be
a major and very efficient process for the dissolution of young clusters in the
spiral galaxy NGC 1313. Performing stellar PSF photometry on archival HST/ACS
images of the galaxy, we find that a large fraction of early B-type stars are
seen outside of star clusters and well spread within the galactic disk,
consistent with the scenario of infant mortality. We also calculate the UV flux
produced by the stars in and out the clusters and find that 75 to 90% of the UV
flux in NGC 1313 is produced by stars outside the clusters. These results
suggest that the infant mortality of star clusters is probably the underlying
cause of the diffuse UV emission in starburst galaxies. Infant mortality would
also explain the numerous B-type stars observed in the background field of our
Galaxy as well. We exclude the possibility that unresolved low-mass star
clusters and scaled OB associations might be the main source for the diffuse UV
emission.Comment: 5 pages, 3 figures, accepted for publication in the Astrophysical
Journal Letter
The Ungovernable Governess:The Figure of the Governess in the Victorian Sensation Novel of the 1860s.
This dissertation will examine the figure of the governess in the Victorian Sensation Novels of the 1860s in order to determine if sensation fiction in this period was inevitably concerned with portraying the ungovernable side of femininity. The primary focus will be on the female protagonist in Mary Elizabeth Braddonâs Lady Audleyâs Secret, Wilkie Collins Armadale, Louisa May Alcottâs âBehind a Mask,â and Ellen Woodâs East Lynne.1 The effects of the moral and social climate of the nineteenth century and the influence the historical governess had on these works will be examined. The hypothesis that Braddon, Collins, Alcott, and Wood use the governess to depict various forms of female non-conformity in order to comment on the limitations and injustices of the womanâs position in a male dominated society will be considered, particularly in relation to the depiction of Victorian matrimony and the sexual double standard. Under discussion will be the liminal position of the governess and the way in which these villainous and deviant women use masquerade and their position in ways that tend towards deception. The motivation behind the actions of these transgressive females will also be discussed, particularly the significance of poverty and social position on their ungovernable behaviour, and the extent to which these texts and the governess figure can be seen as feminist will be explored.
Negotiating healthy trade in Australia: health impact assessment of the proposed Trans-Pacific Partnership Agreement
Drawing on leaked texts of potential provisions of the proposed Trans-Pacific Partnership Agreement, this health impact assessment found the potential for negative impacts in the cost of medicines, tobacco control policies, alcohol control policies, and food labeling.
Overview
The Centre for Health Equity Training Research and Evaluation (CHETRE) has been working with a group of Australian academics and non-government organisations interested in the health of the Australian population to carry out a health impact assessment (HIA) on the Trans-Pacific Partnership Agreement (TPP) negotiations.
In the absence of official publicly available drafts of the trade agreement, the health impact assessment drew on leaked texts of potential provisions and formulated policy scenarios based on high priority health policies that could be affected by the TPP. The HIA found the potential for negative impacts in each of the four areas under investigation: the cost of medicines; tobacco control policies; alcohol control policies; and food labeling.
In each of these areas, the HIA report traces the relevant proposed provisions through to their likely effects on the policy scenarios onto the likely impact on the health of Australians, focusing particularly on vulnerable groups in the Australian community.
The report makes a number of recommendations to DFAT regarding the TPP provisions and to the Australian Government regarding the TPP negotiating process
Doctor of Philosophy
dissertationShunt catheter obstruction due to the foreign body host response is a serious problem in the treatment of hydrocephalus. Our goal was to reduce inflammatory cell adhesion on silicone catheters in an effort to limit shunt obstruction. We investigated chemical and mechanical cues that may influence macrophage and astrocyte adhesion, and using this knowledge, examined pertinent catheter modifications. A novel in vitro bioreactor, capable of measuring dependencies between macrophage and astrocyte adhesion, intracranial flow rate, pressure, pulsation frequency, and protein concentration, was developed and tested. Results demonstrated that a combination of chemical cues (particularly surface chemistry) and mechanical cues (particularly shear stress) influenced macrophage and astrocyte attachment to shunt catheters. The surface chemistry of the catheter was modified using long term coatings with anti-inflammatory capabilities including poly(ethylene) glycol and N-acetyl-L-cysteine, both of which significantly inhibited macrophage and astrocyte adhesion when tested in the bioreactor. Additionally, the shear stress through ventricular catheter drainage holes was manipulated by changing the diameter of these openings. Data generally suggested that macrophage and astrocyte adhesion decreases with increasing hole size. Two barriers were overcome in this research: (1) the development of an in vitro system capable of testing catheter constructs in a method superior to standard static in vitro culturing; (2) significant surface and architecture modifications that inhibit inflammatory cell adhesion which could be used in future studies to inhibit inflammatory-derived obstruction. Together, the implementation of this system and the modifications to current catheter design will help answer questions of how and why catheters fail
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The endocrine disrupting activities of major industrial chemicals - the phthalate esters and 4-nonylphenol
This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University, 14/11/2000.A number of widely used industrial chemicals have been shown to possess endocrine-disrupting properties. In this thesis, a series of in vitro tests, and an in vivo reproductive performance test with fathead minnows, were used to clarify the extent of estrogenic activity exhibited by the phthalate esters - a class of compound hitherto referred to as 'estrogenic'. Using a recombinant yeast estrogen screen, I demonstrated that a small number of commercially available phthalates showed extremely weak estrogenic activity. The most potently estrogenic phthalate of those tested was BBP, which was approximately one million-fold less potent than 17B-estradiol. The phthalates which were estrogenic in the yeast screen were also mitogenic on estrogen-responsive human breast cancer cells (MCF-7 and ZR-75 cell lines). The most prolifically used phthalate, DEHP, was not estrogenic in any of these assays. The small number of metabolites of phthalate metabolites tested (including
MBuP, MBzP, MEHP and MnOP) were also not estrogenic in the recombinant yeast assay.
The ability of BBP (as the most potently estrogenic phthalate in vitro) to induce a vitellogenic response (an indicator of estrogen exposure) in fathead minnows (Pimephales promelas) exposed via the water was assessed. No induction of vitellogenin was observed, indicating that 100 Jlg BBP/L (a concentration higher than would normally be found in the environment) is not estrogenic to this species of fish under the conditions employed for this experiment. In the same study, fecundity of breeding pairs of fathead minnows was assessed; exposure to BBP was not found to affect reproductive performance in these fish. A possible alternative mechanism of action of the way in which the phthalates induce frequently reported reproductive disorders was observed. Some of the phthalates, and, notably, some of their metabolites, were demonstrated to act as anti-androgens in a recombinant yeast androgen assay. 4-Nonylphenol is another industrial chemical which is used in large volumes, and due to the nature of its use (mainly in detergent formulations), is discharged into water systems via sewage effluents. This chemical has been shown to be estrogenic to fish at the concentrations at which it has been detected in the environment. 4-Nonylphenol was tested for its ability to affect plasma and pituitary gonadotropin levels in female recrudescing rainbow trout (Oncorhynchus mykiss). Plasma and pituitary levels of FSH were suppressed in fish exposed to 10 and 100 Jlg 4-NP/L. In addition, FSH gene expression was reduced in these fish, and also in the fish exposed to 1 Jlg 4-NP/L. Pituitary LH content and gene expression of this hormone were suppressed in the fish exposed to 100-, and 10- and 100 Jlg 4-NP/L respectively. Gonadal development in vertebrates is regulated by FSH. Ovarian development ceased in the fish exposed to 100 JAg 4-NP/L, possibly as a result of the suppression of FSH synthesis and/or release in these fish
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The hidden curriculum of the recognition of prior learning: a case study
This thesis is a case study of a Recognition of Prior Learning (RPL) practice developed in relation to a university post-graduate level diploma course for educators of adults in a South African university.
A review of the literature reveals silences, paradoxes and contradictions around understandings of knowledge, pedagogy, power and identity in RPL. An absence of academic, empirical research at the micro-level of RPL practices is noted. The research foci are concerned with how knowledge(s), pedagogy, power and identity are understood and enacted in and around the case: selected for its intrinsic and atypical qualities and generative interest value.
The research draws theoretical resources from the sociology of education (the work of Bernstein) and from continental philosophy (the work of Foucault). It argues for and adopts a hybrid philosophical position, part social constructionist, part structuralist and part poststructuralist, and an interpretive methodology.
The RPL case in question had a hidden curriculum which rewarded particular ways of thinking and acting. It confirmed prior experiential knowledge that was similar to that valued in the context and in so doing brought the former under the rule of the latter. The RPL pedagogy was ambiguous, presenting an informal style through which power and control were signalled in a disguised way.
'Success' in RPL in this context was dependent on four prior 'affordances': proximity to vertical discourse, being 'schooled' in reflection, a clear pedagogic identity as an educator and a well-developed learner identity. These affordances were socially distributed but not only along race and class lines.
An approach is proposed based on 'knowing the borders and crossing the lines'. This involves theorising relationships between mainstream curricula and pedagogy, RPL curricula and pedagogy, and prior experiential knowledge. It concludes that such approaches might be useful in the broader field of widening participation to higher education
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