869 research outputs found

    Applying a Dynamic Model of Consumer Choice to Guide Brand Development at Jetstar Airways

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    This paper describes the use of a marketing science model by Jetstar, a subsidiary of Australia's leading airline, Qantas, to effectively and profitably compete in the low-cost carrier marketplace. We trace the evolution of the Jetstar strategy from a baseline calibration of its initial position, to its efforts to attain price competitiveness and service parity, followed by its highly focused, cost-effective service delivery strategy. We develop a hierarchical model with parameters estimated at the individual level. This allows us to study not only how service design and pricing initiatives shift the perceived performance of Jetstar relative to its competitors but also how the airline can move market preferences toward areas in which it has competitive advantage. The contribution of the research is substantial. The Jetstar market share went from 14.0% to 18.1% during the first five quarterly waves of the research, and profits went from 79millionin2006−2007,beforethestudywascommissioned,to79 million in 2006-2007, before the study was commissioned, to 124 million in 2008-2009

    Macronutrients mediate the functional relationship between Drosophila and Wolbachia

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    Wolbachia are maternally inherited bacterial endosymbionts that naturally infect a diverse array of arthropods. They are primarily known for their manipulation of host reproductive biology, and recently, infections with Wolbachia have been proposed as a new strategy for controlling insect vectors and subsequent human-transmissible diseases. Yet, Wolbachia abundance has been shown to vary greatly between individuals and the magnitude of the effects of infection on host life-history traits and protection against infection is correlated to within-host Wolbachia abundance. It is therefore essential to better understand the factors that modulate Wolbachia abundance and effects on host fitness. Nutrition is known to be one of the most important mediators of host-symbiont interactions. Here, we used nutritional geometry to quantify the role of macronutrients on insect-Wolbachia relationships in Drosophila melanogaster. Our results show fundamental interactions between diet composition, host diet selection, Wolbachia abundance and effects on host lifespan and fecundity. The results and methods described here open a new avenue in the study of insect-Wolbachia relationships and are of general interest to numerous research disciplines, ranging from nutrition and life-history theory to public health

    Suicide Among Aboriginal People in Canada

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    This report looks at the complex issues that surround Aboriginal suicide in Canad

    Solving the Bethe-Salpeter equation for bound states of scalar theories in Minkowski space

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    We apply the perturbation theory integral representation (PTIR) to solve for the bound state Bethe-Salpeter (BS) vertex for an arbitrary scattering kernel, without the need for any Wick rotation. The results derived are applicable to any scalar field theory (without derivative coupling). It is shown that solving directly for the BS vertex, rather than the BS amplitude, has several major advantages, notably its relative simplicity and superior numerical accuracy. In order to illustrate the generality of the approach we obtain numerical solutions using this formalism for a number of scattering kernels, including cases where the Wick rotation is not possible.Comment: 28 pages of LaTeX, uses psfig.sty with 5 figures. Also available via WWW at http://www.physics.adelaide.edu.au/theory/papers/ADP-97-10.T248-abs.html or via anonymous ftp at ftp://bragg.physics.adelaide.edu.au/pub/theory/ADP-97-10.T248.ps A number of (crucial) typographical errors in Appendix C corrected. To be published in Phys. Rev. D, October 199

    Lineage-specific expansion of proteins exported to erythrocytes in malaria parasites

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    BACKGROUND: The apicomplexan parasite Plasmodium falciparum causes the most severe form of malaria in humans. After invasion into erythrocytes, asexual parasite stages drastically alter their host cell and export remodeling and virulence proteins. Previously, we have reported identification and functional analysis of a short motif necessary for export of proteins out of the parasite and into the red blood cell. RESULTS: We have developed software for the prediction of exported proteins in the genus Plasmodium, and identified exported proteins conserved between malaria parasites infecting rodents and the two major causes of human malaria, P. falciparum and P. vivax. This conserved 'exportome' is confined to a few subtelomeric chromosomal regions in P. falciparum and the synteny of these and surrounding regions is conserved in P. vivax. We have identified a novel gene family PHIST (for Plasmodium helical interspersed subtelomeric family) that shares a unique domain with 72 paralogs in P. falciparum and 39 in P. vivax; however, there is only one member in each of the three species studied from the P. berghei lineage. CONCLUSION: These data suggest radiation of genes encoding remodeling and virulence factors from a small number of loci in a common Plasmodium ancestor, and imply a closer phylogenetic relationship between the P. vivax and P. falciparum lineages than previously believed. The presence of a conserved 'exportome' in the genus Plasmodium has important implications for our understanding of both common mechanisms and species-specific differences in host-parasite interactions, and may be crucial in developing novel antimalarial drugs to this infectious disease

    Efficacy and safety of oral methazolamide in patients with type 2 diabetes: A 24-week, placebo-controlled, double-blind study

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    OBJECTIVE To evaluate the safety and efficacy of methazolamide as a potential therapy for type 2 diabetes. RESEARCH DESIGN AND METHODS This double-blind, placebo-controlled study randomized 76 patients to oral methazolamide (40 mg b.i.d.) or placebo for 24 weeks. The primary efficacy end point for methazolamide treatment was a placebo-corrected reduction in HbA1c from baseline after 24 weeks (ΔHbA1c). RESULTS Mean ± SD baseline HbA1c was 7.1 ± 0.7% (54 ± 5 mmol/mol; n = 37) and 7.4 ± 0.6% (57 ± 5 mmol/mol; n = 39) in the methazolamide and placebo groups, respectively. Methazolamide treatment was associated with a ΔHbA1c of –0.39% (95% CI –0.82, 0.04; P < 0.05) (–4.3 mmol/mol [–9.0, 0.4]), an increase in the proportion of patients achieving HbA1c ≤6.5% (48 mmol/mol) from 8 to 33%, a rapid reduction in alanine aminotransferase (∼10 units/L), and weight loss (2%) in metformin-cotreated patients. CONCLUSIONS Methazolamide is the archetype for a new intervention in type 2 diabetes with clinical benefits beyond glucose control

    Effect of COVID-19 on presentations of decompensated liver disease in Scotland

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    BACKGROUND AND AIMS: SARS-CoV-2 and consequent pandemic has presented unique challenges. Beyond the direct COVID-related mortality in those with liver disease, we sought to determine the effect of lockdown on people with liver disease in Scotland. The effect of lockdown on those with alcohol-related disease is of interest; and whether there were associated implications for a change in alcohol intake and consequent presentations with decompensated disease. METHODS: We performed a retrospective analysis of patients admitted to seven Scottish hospitals with a history of liver disease between 1 April and 30 April 2020 and compared across the same time in 2017, 2018 and 2019. We also repeated an intermediate assessment based on a single centre to examine for delayed effects between 1 April and 31 July 2020. RESULTS: We found that results and outcomes for patients admitted in 2020 were similar to those in previous years in terms of morbidity, mortality, and length of stay. In the Scotland-wide cohort: admission MELD (Model for End-stage Liver Disease) (16 (12–22) vs 15 (12–19); p=0.141), inpatient mortality ((10.9% vs 8.6%); p=0.499) and length of stay (8 days (4–15) vs 7 days (4–13); p=0.140). In the Edinburgh cohort: admission MELD (17 (12–23) vs 17 (13–21); p=0.805), inpatient mortality ((13.7% vs 10.1%; p=0.373) and length of stay (7 days (4–14) vs 7 days (3.5–14); p=0.525)). CONCLUSION: This assessment of immediate and medium-term lockdown impacts on those with chronic liver disease suggested a minimal effect on the presentation of decompensated liver disease to secondary care

    The GALAH survey: Milky Way disc metallicity and alpha-abundance trends in combined APOGEE-GALAH catalogues

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    GALAH and APOGEE are two high resolution multi object spectroscopic surveys that provide fundamental stellar parameters and multiple elemental abundance estimates for >> 400,000 stars in the Milky Way. They are complimentary in both sky coverage and wavelength regime. Thus combining the two surveys will provide us a large sample to investigate the disc metallicity and alpha abundance trends. We use the Cannon data-driven approach selecting training sets from among ∼\sim20,000 stars in common for the two surveys to predict the GALAH scaled stellar parameters from APOGEE spectra as well as APOGEE scaled stellar parameters from GALAH spectra. We provide two combined catalogues with GALAH scaled and APOGEE scaled stellar parameters each having ∼\sim500,000 stars after quality cuts. With ∼\sim470,000 stars that are common in both these catalogues, we compare the GALAH scaled and APOGEE scaled metallicity distribution functions (MDF), radial and vertical metallicity gradients as well as the variation of [α\alpha/Fe] vs [Fe/H] trends along and away from the Galactic mid plane. We find mean metallicities of APOGEE scaled sample to be higher compared to that for the GALAH scaled sample. We find similar [α\alpha/Fe] vs [Fe/H] trends using both samples consistent with previous observational as well as simulation based studies. Radial and vertical metallicity gradients derived using the two survey scaled samples are consistent except in the inner and outer Galactocentric radius bins. Our gradient estimates in the solar neighborhood are also consistent with previous studies and are backed by larger sample size compared to previous works.Comment: 21 pages, 19 figures, submitted to MNRA

    Soft x-ray measurements of z

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    This article reports the experimental characterization of a z-pinch driven-vacuum hohlraum. The authors have measured soft x-ray fluxes of 5 x 10{sup 12} W/cm{sup 2} radiating from the walls of hohlraums which are 2.4--2.5 cm in diameter by 1 cm tall. The x-ray source used to drive these hohlraums was a z-pinch consisting of a 300 wire tungsten array driven by a 2 MA, 100 ns current pulse. In this hohlraum geometry, the z-pinch x-ray source can produce energies in excess of 800 kJ and powers in excess of 100 TW to drive these hohlraums. The x-rays released in these hohlraums represent greater than a factor of 25 in energy and more than a factor of three in x-ray power over previous laboratory-driven hohlraums
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