Protection of Coastal Infrastructure under Rising Flood Risk

The 2005 hurricane season was particularly damaging to the United States, contributing to significant losses to energy infrastructure—much of it the result of flooding from storm surge during hurricanes Katrina and Rita. In 2012, Hurricane Sandy devastated New York City and Northern New Jersey. Research suggests that these events are not isolated, but rather foreshadow a risk that is to continue and likely increase with a changing climate. Extensive energy infrastructure is located along the U.S. Atlantic and Gulf coasts, and these facilities are exposed to an increasing risk of flooding. We study the combined impacts of anticipated sea level rise, hurricane activity and subsidence on energy infrastructure with a first application to Galveston Bay. Using future climate conditions as projected by four different Global Circulation Models (GCMs), we model the change in hurricane activity from present day climate conditions in response to a climate projected in 2100 under the IPCC A1B emissions scenario. We apply the results from hurricane runs from each model to the SLOSH model to investigate the projected change in frequency and distribution of surge heights across climates. Further, we incorporate uncertainty surrounding the magnitude of sea level rise and subsidence, resulting in more detailed projections of risk levels for energy infrastructure over the next century. Applying this model of changing risk exposure, we apply a dynamic programming cost-benefit analysis to the adaptation decision.Thanks are due to Professor Kerry Emanuel for his guidance in the application of his hurricane analysis. Any errors in its application are attributable to the authors. The authors gratefully acknowledge the financial support for this work provided by the MIT Joint Program on the Science and Policy of Global Change through a consortium of industrial sponsors and Federal grants with special support from the U.S. Department of Energy (DE-FE02-94ER61937). N. L. was supported by the NOAA Climate and Global Change Postdoctoral Fellowship Program, administered by the University Corporation for Atmospheric Research

Histopathological analysis and in situ localisation of Australian tiger snake venom in two clinically envenomed domestic animals

Objective: To assess histopathological changes in clinically envenomed tiger snake patients and identify tissue specific localisation of venom toxins using immunohistochemistry. Samples: One feline and one canine patient admitted to the Murdoch Pet Emergency Centre (MPEC), Murdoch University with tiger snake (Notechis sp.) envenoming. Both patients died as a result of envenomation. Non-envenomed tissue was also collected and used for comparison. Methodology: Biopsy samples (heart, lung, kidney andskeletal muscle tissue) were retrieved 1-2 h post death and processed for histopathological examination using Haemotoxylin and Eosin, Martius Scarlet Blue and Periodic Acid Schiff staining. Tissues were examined by light microscopy and tissue sections subjected to immunohistochemical staining using in-house generated monoclonal and polyclonal antibodies against Notechis venoms. Results: Venom-induced pathological changes were observed in the lungs, kidneys and muscle tissue of both patients. Evidence, not previously noted, of procoagulant venom effects were apparent, with formed thrombi in the heart, lungs (small fibrillar aggregates and larger, discrete thrombi) and kidneys. Immunohistochemical assays revealed venom present in the pulmonary tissue, in and around the glomerular capsule and surrounding tubules in renal tissue and scattered throughout the Gastrocnemius muscle tissue. Conclusion: This work has shown pathological evidence of procoagulant venom activity supporting previous suggestions that an initial thrombotic state occurs in envenomed patients. We have shown that venom toxins are able to be localised to specific tissues, in this case, venom was detected in the lung, kidney and muscle tissues of clinically envenomed animals. Future work will examine specific toxin localisation using monoclonal antibodies and identify if antivenom molecules are able to reach their target tissues

The Local Group Census: planetary nebulae in Sextans B

Five planetary nebulae (PNe) have been discovered in the nearby dwarf irregular galaxy. Emission line images were obtained using the Wide Field Camera of the 2.5m Isaac Newton Telescope (INT) at La Palma (Spain). The candidate PNe were identified by their point-like appearance and relatively strong [OIII] emission-line fluxes. They are located within a galactocentric distance of 2.8 arcmin, corresponding to 1.1 kpc at the distance of Sextans B. Luminosities are in the range 1800--5600Lsolar. Sextans B is one of the smallest dwarf irregular galaxies with a PN population. The number of PNe detected suggest an enhanced star formation rate between 1 and 5 Gyr ago.Comment: 7 pages, 2 figure

Developing a health state classification system from NEWQOL for epilepsy using classical psychometric techniques and Rasch analysis: a technical report

Aims: Resource allocation amongst competing health care interventions is informed by evidence of both clinical- and cost-effectiveness. Cost-utility analysis is increasingly used to assess cost effectiveness through the use of Quality Adjusted Life Years (QALYs). This requires health state values. Generic measures of health related quality of life (HRQL) are usually used to produce these values, but there are concerns about their relevance and sensitivity in epilepsy. This study develops a health state classification system for epilepsy from the NEWQOL battery, a validated questionnaire measuring QoL in epilepsy. The classification system will be amenable to valuation for calculating QALYs. Methods: Factor and other psychometric analyses were undertaken to investigate the factor structure of the battery, and assess the validity and responsiveness of the items. These analyses were used alongside Rasch analysis to select the dimensions included in the classification system, and the items used to represent each domain. Analysis was carried out on a trial dataset of patients with epilepsy (n=1611). Rasch and factor analysis were performed on one half of the sample and validated on the remaining half. Dimensions and items were selected that performed well across all analyses. Results: The battery was found to demonstrate reliability and validity but responsiveness across time periods for many of the items was low. A six dimension classification system was developed: worry about seizures, depression, memory, cognition, stigmatism and control, each with four response levels. Conclusions: It is feasible to develop a health state classification system from a battery of instruments using a combination of classical psychometric, factor and Rasch analysis. This is the first condition-specific health state classification developed for epilepsy and the next stage will produce preference weights to enable the measure to be used in cost-utility analysis.quality adjusted life years; health related quality of life; Rasch analysis; preference-based measures of health; health states; epilepsy

Discovery of Five Recycled Pulsars in a High Galactic Latitude Survey

We present five recycled pulsars discovered during a 21-cm survey of approximately 4,150 deg^2 between 15 deg and 30 deg from the galactic plane using the Parkes radio telescope. One new pulsar, PSR J1528-3146, has a 61 ms spin period and a massive white dwarf companion. Like many recycled pulsars with heavy companions, the orbital eccentricity is relatively high (~0.0002), consistent with evolutionary models that predict less time for circularization. The four remaining pulsars have short spin periods (3 ms < P < 6 ms); three of these have probable white dwarf binary companions and one (PSR J2010-1323) is isolated. PSR J1600-3053 is relatively bright for its dispersion measure of 52.3 pc cm^-3 and promises good timing precision thanks to an intrinsically narrow feature in its pulse profile, resolvable through coherent dedispersion. In this survey, the recycled pulsar discovery rate was one per four days of telescope time or one per 600 deg^2 of sky. The variability of these sources implies that there are more millisecond pulsars that might be found by repeating this survey.Comment: 15 pages, 3 figures, accepted for publication in Ap

3,3′-Diindolylmethane and paclitaxel act synergistically to promote apoptosis in HER2/neu human breast cancer cells

Background. HER2/neu positive breast tumors are difficult to treat. About 25 to 30% of invasive breast tumors overexpress the HER2/neu oncogene. These tumors are aggressive and become resistant to chemotherapeutic drugs. 3,3′-diindolylmethane (DIM), the active metabolite of indole-3-carbinol, a naturally occurring compound found in cruciferous vegetables, has been found to have anti-cancer properties in both humans and animals. DIM has been shown to induce cell cycle arrest and apoptosis in animal breast cancer models. Because HER2/neu overexpression confers resistance to paclitaxel, and DIM has anti-tumor effects, we hypothesized that DIM will enhance the cytotoxic effects of paclitaxel, a common taxane drug, on human Her2/neu breast cancer cells by potentiating its effect on cell cycle and stimulating apoptosis. Methods. The MDA-MB-435eB1 human Her2/neu breast cancer cells were treated with varying concentrations of DIM and paclitaxel. The cells were analyzed at different time points (24, 48, and 72 h). Proliferation was measured by a commercial cell proliferation assay (Promega Procheck Assay). Cell-cycle analysis and apoptosis were determined by flow cytometry. Western blot analysis was performed on to determine the effect of DIM and/or paclitaxel on the proteins involved in apoptosis, and epidermal growth factor-induced activation of HER2/neu and ERK1/2 signaling proteins. Results. Both DIM and paclitaxel exhibited time and concentration dependent inhibition of cell proliferation. TUNEL assay indicated that the combination also increased the number of apoptotic cells more than either agent alone. The presence of cleaved poly (ADPRibose) polymerase (PARP) significantly increased in the combination treatment, whereas Bcl-2 is decreased. DIM alone decreased the activation of the Her2/neu receptor; the combination decreased the activation of ERK1/ERK2. Conclusions. DIM in combination with paclitaxel synergistically inhibits growth of Her2/neu human breast cancer cells through G2M phase cell-cycle arrest and induction of apoptosis/necrosis. The Her2/neu receptor and its downstream signaling protein ERK1/2 appear to be involved in DIM’s affect on cell growth and differentiation, whereas apoptosis appears to be mediated through the mitochondrial pathway (Bcl-2/ PARP). It appears DIM, a naturally occurring, nontoxic compound, may be a beneficial addition to a traditional (taxane-based) chemotherapy regimen

Modelling the Seasonal Epidemics of Respiratory Syncytial Virus in Young Children

BACKGROUND Respiratory syncytial virus (RSV) is a major cause of paediatric morbidity. Mathematical models can be used to characterise annual RSV seasonal epidemics and are a valuable tool to assess the impact of future vaccines. OBJECTIVES Construct a mathematical model of seasonal epidemics of RSV and by fitting to a population-level RSV dataset, obtain a better understanding of RSV transmission dynamics. METHODS We obtained an extensive dataset of weekly RSV testing data in children aged less than 2 years, 2000-2005, for a birth cohort of 245,249 children through linkage of laboratory and birth record datasets. We constructed a seasonally forced compartmental age-structured Susceptible-Exposed-Infectious-Recovered-Susceptible (SEIRS) mathematical model to fit to the seasonal curves of positive RSV detections using the Nelder-Mead method. RESULTS From 15,830 specimens, 3,394 were positive for RSV. RSV detections exhibited a distinct biennial seasonal pattern with alternating sized peaks in winter months. Our SEIRS model accurately mimicked the observed data with alternating sized peaks using disease parameter values that remained constant across the 6 years of data. Variations in the duration of immunity and recovery periods were explored. The best fit to the data minimising the residual sum of errors was a model using estimates based on previous models in the literature for the infectious period and a slightly lower estimate for the immunity period. CONCLUSIONS Our age-structured model based on routinely collected population laboratory data accurately captures the observed seasonal epidemic curves. The compartmental SEIRS model, based on several assumptions, now provides a validated base model. Ranges for the disease parameters in the model that could replicate the patterns in the data were identified. Areas for future model developments include fitting climatic variables to the seasonal parameter, allowing parameters to vary according to age and implementing a newborn vaccination program to predict the effect on RSV incidence.HCM is funded by National Health and Medical Research Council Fellowship #1034254

The Planetary Nebula Luminosity Function at the Dawn of Gaia

The [O III] 5007 Planetary Nebula Luminosity Function (PNLF) is an excellent extragalactic standard candle. In theory, the PNLF method should not work at all, since the luminosities of the brightest planetary nebulae (PNe) should be highly sensitive to the age of their host stellar population. Yet the method appears robust, as it consistently produces < 10% distances to galaxies of all Hubble types, from the earliest ellipticals to the latest-type spirals and irregulars. It is therefore uniquely suited for cross-checking the results of other techniques and finding small offsets between the Population I and Population II distance ladders. We review the calibration of the method and show that the zero points provided by Cepheids and the Tip of the Red Giant Branch are in excellent agreement. We then compare the results of the PNLF with those from Surface Brightness Fluctuation measurements, and show that, although both techniques agree in a relative sense, the latter method yields distances that are ~15% larger than those from the PNLF. We trace this discrepancy back to the calibration galaxies and argue that, due to a small systematic error associated with internal reddening, the true distance scale likely falls between the extremes of the two methods. We also demonstrate how PNLF measurements in the early-type galaxies that have hosted Type Ia supernovae can help calibrate the SN Ia maximum magnitude-rate of decline relation. Finally, we discuss how the results from space missions such as Kepler and Gaia can help our understanding of the PNLF phenomenon and improve our knowledge of the physics of local planetary nebulae.Comment: 12 pages, invited review at the conference "The Fundamental Cosmic Distance Scale: State of the Art and Gaia Perspective", to appear in Astrophysics and Space Scienc

An XMM-Newton view of Planetary Nebulae in the Small Magellanic Cloud. The X-ray luminous central star of SMP SMC 22

During an X-ray survey of the Small Magellanic Cloud, carried out with the XMM-Newton satellite, we detected significant soft X-ray emission from the central star of the high-excitation planetary nebula SMP SMC 22. Its very soft spectrum is well fit with a non local thermodynamical equilibrium model atmosphere composed of H, He, C, N, and O, with abundances equal to those inferred from studies of its nebular lines. The derived effective temperature of 1.5x10^5 K is in good agreement with that found from the optical/UV data. The unabsorbed flux in the 0.1-0.5 keV range is about 3x10^{-11} erg cm^-2 s^-1, corresponding to a luminosity of 1.2x10^37 erg/s at the distance of 60 kpc. We also searched for X-ray emission from a large number of SMC planetary nebulae, confirming the previous detection of SMP SMC 25 with a luminosity of (0.2-6)x10^35 erg/s (0.1-1 keV). For the remaining objects that were not detected, we derived flux upper limits corresponding to luminosity values from several tens to hundreds times smaller than that of SMP SMC 22. The exceptionally high X-ray luminosity of SMP SMC 22 is probably due to the high mass of its central star, quickly evolving toward the white dwarf's cooling branch, and to a small intrinsic absorption in the nebula itself.Comment: Accepted for publication on Astronomy and Astrophysic