Variational derivation of two-component Camassa-Holm shallow water system

By a variational approach in the Lagrangian formalism, we derive the nonlinear integrable two-component Camassa-Holm system (1). We show that the two-component Camassa-Holm system (1) with the plus sign arises as an approximation to the Euler equations of hydrodynamics for propagation of irrotational shallow water waves over a flat bed. The Lagrangian used in the variational derivation is not a metric.Comment: to appear in Appl. Ana

Dysfunction of Nrf-2 in CF Epithelia Leads to Excess Intracellular H2O2 and Inflammatory Cytokine Production

Cystic fibrosis is characterized by recurring pulmonary exacerbations that lead to the deterioration of lung function and eventual lung failure. Excessive inflammatory responses by airway epithelia have been linked to the overproduction of the inflammatory cytokine IL-6 and IL-8. The mechanism by which this occurs is not fully understood, but normal IL-1β mediated activation of the production of these cytokines occurs via H2O2 dependent signaling. Therefore, we speculated that CFTR dysfunction causes alterations in the regulation of steady state H2O2. We found significantly elevated levels of H2O2 in three cultured epithelial cell models of CF, one primary and two immortalized. Increases in H2O2 heavily contributed to the excessive IL-6 and IL-8 production in CF epithelia. Proteomic analysis of three in vitro and two in vivo models revealed a decrease in antioxidant proteins that regulate H2O2 processing, by ≥2 fold in CF vs. matched normal controls. When cells are stimulated, differential expression in CF versus normal is enhanced; corresponding to an increase in H2O2 mediated production of IL-6 and IL-8. The cause of this redox imbalance is a decrease by ∼70% in CF cells versus normal in the expression and activity of the transcription factor Nrf-2. Inhibition of CFTR function in normal cells produced this phenotype, while N-acetyl cysteine, selenium, an activator of Nrf-2, and the overexpression of Nrf-2 all normalized H2O2 processing and decreased IL-6 and IL-8 to normal levels, in CF cells. We conclude that a paradoxical decrease in Nrf-2 driven antioxidant responses in CF epithelia results in an increase in steady state H2O2, which in turn contributes to the overproduction of the pro-inflammatory cytokines IL-6 and IL-8. Treatment with antioxidants can ameliorate exaggerated cytokine production without affecting normal responses

Global patient outcomes after elective surgery: prospective cohort study in 27 low-, middle- and high-income countries.

BACKGROUND: As global initiatives increase patient access to surgical treatments, there remains a need to understand the adverse effects of surgery and define appropriate levels of perioperative care. METHODS: We designed a prospective international 7-day cohort study of outcomes following elective adult inpatient surgery in 27 countries. The primary outcome was in-hospital complications. Secondary outcomes were death following a complication (failure to rescue) and death in hospital. Process measures were admission to critical care immediately after surgery or to treat a complication and duration of hospital stay. A single definition of critical care was used for all countries. RESULTS: A total of 474 hospitals in 19 high-, 7 middle- and 1 low-income country were included in the primary analysis. Data included 44 814 patients with a median hospital stay of 4 (range 2-7) days. A total of 7508 patients (16.8%) developed one or more postoperative complication and 207 died (0.5%). The overall mortality among patients who developed complications was 2.8%. Mortality following complications ranged from 2.4% for pulmonary embolism to 43.9% for cardiac arrest. A total of 4360 (9.7%) patients were admitted to a critical care unit as routine immediately after surgery, of whom 2198 (50.4%) developed a complication, with 105 (2.4%) deaths. A total of 1233 patients (16.4%) were admitted to a critical care unit to treat complications, with 119 (9.7%) deaths. Despite lower baseline risk, outcomes were similar in low- and middle-income compared with high-income countries. CONCLUSIONS: Poor patient outcomes are common after inpatient surgery. Global initiatives to increase access to surgical treatments should also address the need for safe perioperative care. STUDY REGISTRATION: ISRCTN5181700

Doiba manual: using PIXE and PIGE to their full potential with doiba.

In the early 1980s, Eric Clayton developed a software package for the analysis of Proton Induced X-Ray Emission (PIXE) spectra at the Australian Nuclear Science and Technology Organisation (ANSTO). This package was called PIXAN and it is based on work by D.D. Cohen et al. and E. Clayton et al. The package is optimised for the batch analysis of a large number of similar samples. It uses a 2 step process to analyse PIXE spectra. Command line programs controlled by run control files that contain the parameters of the experiment facilitate the 2 steps of the analysis

Improved resolution and sensitivity on the ANSTO microprobe and it's application to μ-PIXE.

We report on the improved spatial resolution of the ANSTO heavy ion microprobe, achieved through the use of a higher brightness ion source for hydrogen. The improved resolution will be demonstrated for applications of μ-PIXE. With the higher brightness source, a 3 μm resolution was achieved for μ-PIXE elemental analysis. This is illustrated in high resolution images of nickel (Ni)-hyperaccumulating Hybanthus floribundus subsp. floribundus leaf tissues, where individual cells were clearly visible in the acquired elemental images. The higher resolution images illustrated that Ni was localised in epidermal cell walls. © 2009, Elsevier Ltd

Silicon detector dead layer thickness estimates using proton bremsstrahlung from low atomic number targets.

Proton-induced bremsstrahlung radiation in the 1-5 keV energy range has been used to estimate the silicon dead layer thickness in a Si(Li) detector. This novel technique does not require accurate bremsstrahlung cross sections with x-ray energy; it just assumes these cross sections and hence the efficiency corrected yield is both smooth and continuous across the Si K edge at 1.838 keV. © 2008, Wiley-Blackwell. The definitive version is available at www3.interscience.wiley.co

Towards a better understanding and prediction of the bremsstrahlung background in PIXE spectra.

Murozono and Ishii et al recently published theoretical QFEB, SEB and AB bremsstrahlung cross sections which, when modified by typical X-ray detection efficiencies, provide excellent predictions of the backgrounds in PIXE spectra for a range of light target matrices.Australian Institute of Nuclear Science and Engineering (AINSE); Vacuum Society of Australia (VSA); Australian Research Council (ARC); Australian Research Network for Advanced Materials (ARNAM); JAVAC; Nanotechnology Network; ThermoFisher Scientifi

Development of accelerator based micro IBA techniques for the study of environmental samples and material characterisation.

The Australian Nuclear Science and Technology Organisation (ANSTO) is a research establishment of around 950 people located approximately 30 km south west of Sydney, Australia. ANSTO has several research institutes, including Bragg, Radiopharm, Materials and Environment. These institutes alone include about 300 research and technical support staff. ANSTO's major neutron facility is the Open Pool Australian Light Water Reactor (OPAL). It is a 20 MW pool reactor using low enriched uranium fuel, and cooled by water. It is a multipurpose facility for radioisotope production, irradiation services and neutron beam research.International Atomic Energy Agenc

Oxidation of polyethylene implanted with low energy magnesium ions

The oxidation of polyethylene implanted with low energy, i.e. 25–50 keV, Mg ions to fluences from 5 × 1012–5 × 1016 ions/cm2 was studied. Rutherford back-scattering spectroscopy showed all implanted samples gained oxygen but the distribution did not match that of the implanted Mg. An increase in carbon content was also observed for the near-surface region. Depth profiles of hydrogen were obtained via elastic recoil detection analysis, showing that hydrogen was lost throughout and beyond the range of the Mg ions, producing unsaturated and chemically active sites available for oxidation. Fourier-transform infrared spectroscopy revealed the formation of carbon–oxygen bonding such as carbonyl groups, but showed no evidence of oxidised magnesium. Raman spectroscopy showed disordered and graphitic carbon bonding configurations were created by the irradiation, but no evidence of oxidised magnesium. The implantation of films to high fluence produced a carbonized surface-layer that made the irradiated polymer more resistant to oxidation. © 2013, Elsevier B.V