Detailed two-dimensional modelling of a complex bridge arrangement – McKinlay River No. 2 Bridge, Alice Springs to Darwin railway

The Alice Springs – Darwin Railway Project involved the construction of 1420 km of new standard gauge track between Alice Springs and Darwin, including the McKinlay River No. 2 Bridge. During the 2006, 2007 and 2008 flood seasons, significant scour occurred around the McKinlay River No. 2 Bridge piers, raising concerns regarding the continuing stability of the structure. The site has complex geometry, with the river approaching the crossing at a significant angle and the remains of the original railway bridge just upstream of the new structure. Owing to the complex arrangement, a detailed 2-D hydrodynamic SOBEK model of the bridge crossing was developed to inform the design of scour protection works at the site. The model was used to analyse a number of options to reduce the potential for scour, and allowed for the scour protection works to be optimised for conditions at the site. The designed protection works were constructed in 2011, and have performed well in several subsequent flow events

The art of HIV elimination: past and present science

Introduction: Remarkable strides have been made in controlling the HIV epidemic, although not enough to achieve epidemic control. More recently, interest in biomedical HIV control approaches has increased, but substantial challenges with the HIV cascade of care hinder successful implementation. We summarise all available HIV prevention methods and make recommendations on how to address current challenges. Discussion: In the early days of the epidemic, behavioural approaches to control the HIV dominated, and the few available evidence-based interventions demonstrated to reduce HIV transmission were applied independently from one another. More recently, it has become clear that combination prevention strategies targeted to high transmission geographies and people at most risk of infections are required to achieve epidemic control. Biomedical strategies such as male medical circumcision and antiretroviral therapy for treatment in HIV-positive individuals and as preexposure prophylaxis in HIV-negative individuals provide immense promise for the future of HIV control. In resourcerich settings, the threat of HIV treatment optimism resulting in increased sexual risk taking has been observed and there are concerns that as ART roll-out matures in resource-poor settings and the benefits of ART become clearly visible, behavioural disinhibition may also become a challenge in those settings. Unfortunately, an efficacious vaccine, a strategy which could potentially halt the HIV epidemic, remains elusive. Conclusion: Combination HIV prevention offers a logical approach to HIV control, although what and how the available options should be combined is contextual. Therefore, knowledge of the local or national drivers of HIV infection is paramount. Problems with the HIV care continuum remain of concern, hindering progress towards the UNAIDS target of 90-90-90 by 2020. Research is needed on combination interventions that address all the steps of the cascade as the steps are not independent of each other. Until these issues are addressed, HIV elimination may remain an unattainable goal

Magellanic Cloud X-ray Sources: III. Completion of a ROSAT Survey

This paper concludes a series of three papers presenting ROSAT High-Resolution Imager (HRI) observations of unidentified Einstein and serendipitous ROSAT X-ray sources in the direction of the Magellanic Clouds. Accurate positions and fluxes have been measured for these sources. Optical photometry and spectroscopy were obtained to search for identifications in order to determine the physical nature of these sources. The present paper includes new data for 24 objects; identifications are given or confirmed for 30 sources. For six sources optical finding charts showing the X-ray positions are provided. The results from this program are summarized, showing the populations of luminous X-ray sources in the Magellanic Clouds are quite different from those in the Galaxy.Comment: 28 pages, 2 figures; to appear in Astronomical Journa

A Supersoft X-Ray Binary in the Small Magellanic Cloud

Photometric observations of the supersoft X-ray source 1E 0035.4-7230 obtained during two years reveal that the very blue optical counterpart (V (maximum)=20.2, B-V=-0.15, U-B=-1.06) undergoes nearly sinusoidal variations with a period of 0.1719256 days and an amplitude of Delta V~0.3 mag. ROSAT observations show the X-rays vary with approximately the same period. However, either the X-ray minimum precedes the optical minimum by about a quarter cycle or there is a small period difference between the two wavelength regions. We consider that this X-ray source is a close binary, with the optical light coming primarily from an accretion disk surrounding the compact star. Optical spectra show weak, variable He II (4686 Angstrom) emission which probably originates in this disk. Possible interpretations of the light curve are discussed, including X-ray heating of the secondary star. The very broad minimum in the X-ray light curve suggests the X-rays may be scattered in a large accretion disk corona (ADC) which is partially occulted, probably by an azimuthally irregular bulge on the disk rim. If this system lies at the distance of the Small Magellanic Cloud, it radiates near the Eddington luminosity.Comment: 10 pages, 1 table and 3 (of 4) figures as uuencoded compressed Postscript. Also available at http://www.dao.nrc.ca/DAO/SCIENCE/science.htm

Developmentally vitamin D-deficient rats show enhanced prepulse inhibition after acute δ9-tetrahydrocannabinol

Developmental vitamin D (DVD) deficiency has been proposed as a risk factor for schizophrenia. DVD-deficient rats show selective cognitive deficits and novelty-induced hyperlocomotion and enhanced locomotor responses from acute treatment with psychomimetic drugs, such as amphetamine and MK-801. Here we aimed to examine the effect of a drug from a different class of psychomimetic/psychoactive compounds, Δ-tetrahydrocannabinol (THC), on tasks of relevance to the cognitive and positive symptoms of schizophrenia. The aim of this study was to investigate whether DVD deficiency modulates the behavioural effects of THC on tests of delay-dependent memory, sensorimotor gating and locomotion. Adult control and DVD-deficient rats were injected with THC (0, 0.3, 0.6, 1.25, 2.5 mg/kg) 15 min before a delay match to sample (DMTS) task using variable delays (0-24 s). A separate group of rats was injected with either 2.5 mg/kg THC or vehicle before tests of either prepulse inhibition (PPI) of the acoustic startle response or in the open field. Control and DVD-deficient rats showed a similar dose-dependent impairment in performance on the DMTS. The greatest impairment was observed at 2.5 mg/kg for all delays (0-24 s). DVD-deficient rats showed THC-induced enhancement of PPI, which was not observed in control rats. There was no effect of maternal diet on acoustic startle response or locomotor responses in the open field. This study reports the novel findings that DVD-deficient rats were more sensitive to the acute effects of THC on PPI. It appears that prenatal vitamin D deficiency has long-term effects on sensitivity to the behavioural effects of cannabinoids

Key features of palliative care service delivery to Indigenous peoples in Australia, New Zealand, Canada and the United States: A comprehensive review

Background: Indigenous peoples in developed countries have reduced life expectancies, particularly from chronic diseases. The lack of access to and take up of palliative care services of Indigenous peoples is an ongoing concern. Objectives: To examine and learn from published studies on provision of culturally safe palliative care service delivery to Indigenous people in Australia, New Zealand (NZ), Canada and the United States of America (USA); and to compare Indigenous peoples’ preferences, needs, opportunities and barriers to palliative care. Methods: A comprehensive search of multiple databases was undertaken. Articles were included if they were published in English from 2000 onwards and related to palliative care service delivery for Indigenous populations; papers could use quantitative or qualitative approaches. Common themes were identified using thematic synthesis. Studies were evaluated using Daly’s hierarchy of evidence-for-practice in qualitative research. Results: Of 522 articles screened, 39 were eligible for inclusion. Despite diversity in Indigenous peoples’ experiences across countries, some commonalities were noted in the preferences for palliative care of Indigenous people: to die close to or at home; involvement of family; and the integration of cultural practices. Barriers identified included inaccessibility, affordability, lack of awareness of services, perceptions of palliative care, and inappropriate services. Identified models attempted to address these gaps by adopting the following strategies: community engagement and ownership; flexibility in approach; continuing education and training; a whole-of-service approach; and local partnerships among multiple agencies. Better engagement with Indigenous clients, an increase in number of palliative care patients, improved outcomes, and understanding about palliative care by patients and their families were identified as positive achievements. Conclusions: The results provide a comprehensive overview of identified effective practices with regards to palliative care delivered to Indigenous populations to guide future program developments in this field. Further research is required to explore the palliative care needs and experiences of Indigenous people living in urban areas

The surface science of quasicrystals

The surfaces of quasicrystals have been extensively studied since about 1990. In this paper we review work on the structure and morphology of clean surfaces, and their electronic and phonon structure. We also describe progress in adsorption and epitaxy studies. The paper is illustrated throughout with examples from the literature. We offer some reflections on the wider impact of this body of work and anticipate areas for future development. (Some figures in this article are in colour only in the electronic version

Genetic Synthesis of Periodic Protein Materials

Genetic engineering offers a novel approach to the development of advanced polymeric materials, in particular protein-based materials. Biological synthesis provides levels of control of polymer chain architecture that cannot yet be attained by current methods of chemical synthesis. In addition to employing naturally occurring genetic templates artificial genes can be designed to encode completely new materials with customized properties. In the present paper we: 1) review the concepts and technology of creating protein-based materials by genetic engineering, 2) discuss the merits of producing crystalline lamellar proteins by this approach, and 3) review progress made by our group in generating such materials by genetic strategies. Full descriptions appear elsewhere about the parameters to be considered in designing artificial protein genes of this type, the effectiveness of different gene construction and expression strategies utilized by us thus far and, the specific properties of the various materials derived from these efforts (1,2). Progress made by other groups involved in developing periodic proteins by molecular biological strategies are described in refs. 3-8. The latter studies include genetic engineering of artificial silk-like proteins (3,4), poly-aspartylphenylalanine (5), an α/β barrel domain (octarellin; 6), the collagen tripeptide GlyProPro (7) and human tropoelastin (8). Advances with the silk-like proteins (SLP) have been particularly impressive. In addition to producing multi-gram quantities of pure SLP homopolymers, this group has successfully generated block copolymers of SLP interspersed with core peptides of mammalian elastin and the human fibronectin cell attachment element. While publications are still lacking it appears that a numiber of groups are striving to create genetically engineered variants of the repetitive bioadhesive proteins produced by mussels and barnacles (9)

Preventing Running Injuries Using a Pre-Running Exercise Program (PREP): A Pilot Study

Hypothesis: An 8 week supervised PREP implemented prior to a 5k running program will reduce the incidence of RRI\u27s among novice runners training for a 5k below the previously published incidence rates