8,170 research outputs found

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

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    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

    Formation of a quasicrystalline Pb monolayer on the ten-fold surface of the decagonal Al-Ni-Co quasicrystal

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    Lead has been deposited on the ten-fold surface of decagonal Al72Ni11Co17 to form an epitaxial quasicrystalline single-element monolayer. The overlayer grows through nucleation of nanometer-sized irregular islands and the coverage saturates at 1 ML. The overlayer is well-ordered quasiperiodically as evidenced by LEED and Fourier transforms of STM images. Annealing the film to 600 K improves the structural quality, but causes the evaporation of some material such that the film develops pores. Electronic structure measurements using X-ray photoemission spectroscopy indicate that the chemical interaction of the Pb atoms with the substrate is weak.Comment: 12 pages, 5 figure

    Polyaryl ethers and related polysiloxane copolymer molecular coatings preparation and radiation degrdation

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    Poly(arylene ether sulfones) comprise a class of materials known as engineering thermoplastics which have a variety of important applications. These polymers are tough, rigid materials with good mechanical properties over a wide temperature range, and they are processed by conventional methods into products typically having excellent hydrolytic, thermal, oxidative and dimensional stability. Wholly aromatic random copolymers of hydroquinone and biphenol with 4.4 prime dichlorodiphenyl sulfone were synthesized via mechanical nucleophilic displacement. Their structures were characterized and mechanical behavior studied. These tough, ductile copolymers show excellent radiation resistance to electron beam treatment and retain much of the mechanical properties up to at least 700 Mrads under argon

    Nuclear alpha-clustering, superdeformation, and molecular resonances

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    Nuclear alpha-clustering has been the subject of intense study since the advent of heavy-ion accelerators. Looking back for more than 40 years we are able today to see the connection between quasimolecular resonances in heavy-ion collisions and extremely deformed states in light nuclei. For example superdeformed bands have been recently discovered in light N=Z nuclei such as 36^{36}Ar, 40^{40}Ca, 48^{48}Cr, and 56^{56}Ni by γ\gamma-ray spectroscopy. The search for strongly deformed shapes in N=Z nuclei is also the domain of charged-particle spectroscopy, and our experimental group at IReS Strasbourg has studied a number of these nuclei with the charged particle multidetector array {\sc Icare} at the {\sc Vivitron} Tandem facility in a systematical manner. Recently the search for γ\gamma-decays in 24^{24}Mg has been undertaken in a range of excitation energies where previously nuclear molecular resonances were found in 12^{12}C+12^{12}C collisions. The breakup reaction 24^{24}Mg+12+^{12}C has been investigated at Elab_{lab}(24^{24}Mg) = 130 MeV, an energy which corresponds to the appropriate excitation energy in 24^{24}Mg for which the 12^{12}C+12^{12}C resonance could be related to the breakup resonance. Very exclusive data were collected with the Binary Reaction Spectrometer in coincidence with {\sc Euroball IV} installed at the {\sc Vivitron}.Comment: 10 pages, 4 eps figures included. Invited Talk 10th Nuclear Physics Workshop Marie and Pierre Curie, Kazimierz Dolny Poland, Sep. 24-28, 2003; To be published in International Journal of Modern Physics

    Informed consent and medical ordeal: a qualitative study

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    Background Informed consent is a mainstay of clinical practice, with both moral and legal force. Material disclosure about extreme treatments, however, is unlikely to convey the full impact of the experience of treatment. Informed consent may be flawed under such cir-cumstances. Aims To compare expressed satisfaction with pre-treatment information to satisfaction af-ter experiencing autologous stem cell transplantation (ASCT) for recurrent lymphoma. Methods A qualitative, narrative-based cohort study has been conducted in a Teaching hospital Bone Marrow Transplant unit at Westmead Hospital, Sydney, Australia. The cohort consisted of ten transplant recipients and nine of their nominated lay carers. The Outcome measure was satisfaction expressed in narrative interviews at the time of transplantation and three months later. We used discourse analytic techniques to examine the narratives. Results Both patients and carers expressed high satisfaction with the information given by individual clinicians and by speakers at a formal Information Day held before transplanta-tion. At the first interview, neither patients nor carers commented much on the forthcom-ing ordeal of chemotherapy and bone marrow ablation, although all patients had under-gone previous chemotherapy. At the second interview, the ordeal dominated the narratives, and retrospective dissatisfaction with information was common. Conclusions This study suggests that information about treatment theories and protocols can be satisfactorily communicated, but personal experience of suffering defies communi-cation. This finding has serious implications for the practices involved in obtaining informed consent and for the very notion of informed consent. KEY WORDS Autologous stem cell transplantation; haematological malignancies; extreme treatment; medical communication; informed consent

    Stellar Populations of Luminous Evolved Galaxies at z~1.5

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    Observational evidence has been mounting over the past decade that at least some luminous (~2 L*) galaxies have formed nearly all of their stars within a short period of time only 1-2x10^9 years after the Big Bang. These are examples of the first major episodes of star formation in the Universe and provide insights into the formation of the earliest massive galaxies. We have examined in detail the stellar populations of six z~1.5 galaxies that appear to be passively evolving, using both ground and space-based photometry covering rest-frame UV to visible wavelengths. In addition, we have obtained medium-resolution spectroscopy for five of the six galaxies, covering the rest-frame UV portion of the spectrum. Spectral synthesis modeling for four of these galaxies favors a single burst of star formation more than 1 Gyr before the observed epoch. The other two exhibit slightly younger ages with a higher dust content and evidence for a small contribution from either recent star formation or active nuclei. The implied formation redshifts for the oldest of these sources are consistent with previous studies of passive galaxies at high redshift, and improved stellar modeling has shown these results to be quite robust. It now seems clear that any valid galaxy formation scenario must be able to account for these massive (2x10^11 M_sun) galaxies at very early times in the Universe.Comment: 10 pages, 3 figures (2 in color), accepted for publication in Ap

    Informed consent and medical ordeal: a qualitative study

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    Background Informed consent is a mainstay of clinical practice, with both moral and legal force. Material disclosure about extreme treatments, however, is unlikely to convey the full impact of the experience of treatment. Informed consent may be flawed under such cir-cumstances. Aims To compare expressed satisfaction with pre-treatment information to satisfaction af-ter experiencing autologous stem cell transplantation (ASCT) for recurrent lymphoma. Methods A qualitative, narrative-based cohort study has been conducted in a Teaching hospital Bone Marrow Transplant unit at Westmead Hospital, Sydney, Australia. The cohort consisted of ten transplant recipients and nine of their nominated lay carers. The Outcome measure was satisfaction expressed in narrative interviews at the time of transplantation and three months later. We used discourse analytic techniques to examine the narratives. Results Both patients and carers expressed high satisfaction with the information given by individual clinicians and by speakers at a formal Information Day held before transplanta-tion. At the first interview, neither patients nor carers commented much on the forthcom-ing ordeal of chemotherapy and bone marrow ablation, although all patients had under-gone previous chemotherapy. At the second interview, the ordeal dominated the narratives, and retrospective dissatisfaction with information was common. Conclusions This study suggests that information about treatment theories and protocols can be satisfactorily communicated, but personal experience of suffering defies communi-cation. This finding has serious implications for the practices involved in obtaining informed consent and for the very notion of informed consent. KEY WORDS Autologous stem cell transplantation; haematological malignancies; extreme treatment; medical communication; informed consent

    The Assembly of the Red Sequence at z ~ 1: The Color and Spectral Properties of Galaxies in the Cl1604 Supercluster

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    We investigate the properties of the 525 spectroscopically confirmed members of the Cl1604 supercluster at z ~ 0.9 as part of the Observations of Redshift Evolution in Large Scale Environments survey. In particular, we focus on the photometric, stellar mass, morphological, and spectral properties of the 305 member galaxies of the eight clusters and groups that comprise the Cl1604 supercluster. Using an extensive Keck Low-Resolution Imaging Spectrometer (LRIS)/DEep Imaging Multi-Object Spectrograph (DEIMOS) spectroscopic database in conjunction with ten-band ground-based, Spitzer, and Hubble Space Telescope imaging, we investigate the buildup of the red sequence in groups and clusters at high redshift. Nearly all of the brightest and most massive red-sequence galaxies present in the supercluster environment are found to lie within the bounds of the cluster and group systems, with a surprisingly large number of such galaxies present in low-mass group systems. Despite the prevalence of these red-sequence galaxies, we find that the average cluster galaxy has a spectrum indicative of a star-forming galaxy, with a star formation rate between those of z ~ 1 field galaxies and moderate-redshift cluster galaxies. The average group galaxy is even more active, exhibiting spectral properties indicative of a starburst. The presence of massive, red galaxies and the high fraction of starbursting galaxies present in the group environment suggest that significant processing is occurring in group environments at z ~ 1 and earlier. There is a deficit of low-luminosity red-sequence galaxies in all Cl1604 clusters and groups, suggesting that such galaxies transition to the red sequence at later times. Extremely massive (~10^(12)M_☉) red-sequence galaxies routinely observed in rich clusters at z ~ 0 are also absent from the Cl1604 clusters and groups. We suggest that such galaxies form at later times through merging processes. There are significant populations of transition galaxies at intermediate stellar masses (log(M_*)=10.25-10.75) present in the group and cluster environments, suggesting that this range is important for the buildup of the red-sequence mass function at z ~ 1. Through a comparison of the transitional populations present in the Cl1604 cluster and group systems, we find evidence that massive blue-cloud galaxies are quenched earliest in the most dynamically relaxed systems and at progressively later times in dynamically unrelaxed systems

    Beneficial effect of ustekinumab in familial pityriasis rubra pilaris with a new missense mutation in CARD14

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    Pityriasis rubra pilaris (PRP) represents a group of rare chronic inflammatory skin disorders in which ~1 in 20 affected individuals show autosomal dominant inheritance. In such cases, there may be gain-of-function mutations in CARD14, encoding caspase recruitment domain-containing protein 14 (CARD14) that activates the non-canonical nuclear factor-kappa B (NF-κB) pathway, thereby promoting cutaneous inflammation. Here, we report a mother and son with PRP due to a new missense mutation in CARD14 and describe the beneficial clinical effects of ustekinumab, a monoclonal antibody against interleukins-12 and -23, in both subjects. A 49 year-old female and her 20 year-old son had lifelong, generalised, patchy erythematous scale with a few islands of sparing, as well as minor nail ridging and mild palmoplantar keratoderma, features consistent with generalised PRP. Topical steroids, phototherapy and oral retinoids proved ineffective therapies. Following informed consent, Sanger sequencing of CARD14 in both individuals revealed a new heterozygous single nucleotide transversion in exon 16, c.356T>G, resulting in the missense mutation, p.Met119Arg. Ustekinumab, at a dose of 45mg every 12 weeks, brought about a significant physical and emotional improvement in both the mother and son within a few days of the initial dose, which was sustained on maintenance dosing. This report highlights the therapeutic potential of biologics that downregulate NF-kB signalling in familial PRP with mutations in CARD14. This article is protected by copyright. All rights reserved

    Considerations to Model Heart Disease in Women with Preeclampsia and Cardiovascular Disease

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    Preeclampsia is a multifactorial cardiovascular disorder diagnosed after 20 weeks of gestation, and is the leading cause of death for both mothers and babies in pregnancy. The pathophysiology remains poorly understood due to the variability and unpredictability of disease manifestation when studied in animal models. After preeclampsia, both mothers and offspring have a higher risk of cardiovascular disease (CVD), including myocardial infarction or heart attack and heart failure (HF). Myocardial infarction is an acute myocardial damage that can be treated through reperfusion; however, this therapeutic approach leads to ischemic/reperfusion injury (IRI), often leading to HF. In this review, we compared the current in vivo, in vitro and ex vivo model systems used to study preeclampsia, IRI and HF. Future studies aiming at evaluating CVD in preeclampsia patients could benefit from novel models that better mimic the complex scenario described in this article
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