Looking through drumlins: testing the application of ground penetrating radar

ACKNOWLEDGEMENTS We thank the editor, Bernd Kulessa, for his review and support, and John Hiemstra and an anonymous reviewer for helpful comments and suggestions. This work was supported by an equipment loan from the UK Natural Environment Research Council (NERC) Geophysical Equipment Facility (Loan 990) and a University of Aberdeen, College of Physical Sciences’ Research and Teaching Enhancement Fund. All authors are indebted to the NERC Geophysical Equipment Facility staff for training in the use of the antennas and GPS. J.C.E. thanks the Denisons for funding his PhD. We also thank Wharton Hall and Shaw Paddock farms for access to the field sites.Peer reviewedPublisher PD

Using the surface profiles of modern ice masses to inform palaeo-glacier reconstructions

Morphometric study of modern ice masses is useful because many reconstructions of glaciers traditionally draw on their shape for guidance Here we analyse data derived from the surface profiles of 200 modern ice masses-valley glaciers icefields ice caps and ice sheets with length scales from 10(0) to 10(3) km-from different parts of the world Four profile attributes are investigated relief span and two parameters C* and C that result from using Nye s (1952) theoretical parabola as a profile descriptor C* and C respectively measure each profile s aspect ratio and steepness and are found to decrease in size and variability with span This dependence quantifies the competing influences of unconstrained spreading behaviour of ice flow and bed topography on the profile shape of ice masses which becomes more parabolic as span Increases (with C* and C tending to low values of 2 5-3 3 m(1/2)) The same data reveal coherent minimum bounds in C* and C for modern ice masses that we develop into two new methods of palaeo glacier reconstruction In the first method glacial limits are known from moraines and the bounds are used to constrain the lowest palaeo ice surface consistent with modern profiles We give an example of applying this method over a three-dimensional glacial landscape in Kamchatka In the second method we test the plausibility of existing reconstructions by comparing their C* and C against the modern minimum bounds Of the 86 published palaeo ice masses that we put to this test 88% are found to be plausible The search for other morphometric constraints will help us formalise glacier reconstructions and reduce their uncertainty and subjectiveness (C) 2010 Elsevier Ltd All rights reserve

Chandra Spectral and Timing Analysis of Sgr A*'s Brightest X-ray Flares

We analyze the two brightest Chandra X-ray flares detected from Sagittarius A*, with peak luminosities more than 600 x and 245 x greater than the quiescent X-ray emission. The brightest flare has a distinctive double-peaked morphology --- it lasts 5.7 ksec ($\sim 2$ hours), with a rapid rise time of 1500 sec and a decay time of 2500 sec. The second flare lasts 3.4 ksec, with rise and decay times of 1700 sec and 1400 sec. These luminous flares are significantly harder than quiescence: the first has a power law spectral index $\Gamma = 2.06\pm 0.14$ and the second has $\Gamma = 2.03\pm 0.27$, compared to $\Gamma = 3.0\pm0.2$ for the quiescent accretion flow. These spectral indices (as well as the flare hardness ratios) are consistent with previously-detected Sgr A* flares, suggesting that bright and faint flares arise from similar physical processes. Leveraging the brightest flare's long duration and high signal-to-noise, we search for intraflare variability and detect excess X-ray power at a frequency of $\nu \approx 3$ mHz, but show that it is an instrumental artifact and not of astrophysical origin. We find no other evidence (at the 95% confidence level) for periodic or quasi-periodic variability in either flares' time series. We also search for non-periodic excess power but do not find compelling evidence in the power spectrum. Bright flares like these remain our most promising avenue for identifying Sgr A*'s short timescale variability in the X-ray, which may probe the characteristic size scale for the X-ray emission region.Comment: Updated to match published version; 19 pages, 7 figures, 3 table

Varieties of crisis and working conditions: A comparative study between Greece and Serbia

We explore two historically different, yet regionally connected, countries and the way that their weak institutional foundations and long-term economic turbulence have made them unable to overcome crises, leading to the institutionalisation of adverse working conditions. We focus on the outcomes of the systemic crisis in Greece and the transition crisis in Serbia using semi-structured interviews and focus groups with managers and employees in small and medium-sized enterprises (SMEs) in two time periods. We argue that, although the crisis has different origins in the two countries, in both it has led to adverse working conditions becoming institutionalised in organisations and, therefore, less likely to change. Our research explores the institutionalisation of adverse working conditions and offers an understanding of the lived reality of institutions in the way they are experienced by individuals, examining variations in the origins, pressures and outcomes of different types of crises on business practices from an individual perspective

XIPE: the X-ray Imaging Polarimetry Explorer

X-ray polarimetry, sometimes alone, and sometimes coupled to spectral and temporal variability measurements and to imaging, allows a wealth of physical phenomena in astrophysics to be studied. X-ray polarimetry investigates the acceleration process, for example, including those typical of magnetic reconnection in solar flares, but also emission in the strong magnetic fields of neutron stars and white dwarfs. It detects scattering in asymmetric structures such as accretion disks and columns, and in the so-called molecular torus and ionization cones. In addition, it allows fundamental physics in regimes of gravity and of magnetic field intensity not accessible to experiments on the Earth to be probed. Finally, models that describe fundamental interactions (e.g. quantum gravity and the extension of the Standard Model) can be tested. We describe in this paper the X-ray Imaging Polarimetry Explorer (XIPE), proposed in June 2012 to the first ESA call for a small mission with a launch in 2017 but not selected. XIPE is composed of two out of the three existing JET-X telescopes with two Gas Pixel Detectors (GPD) filled with a He-DME mixture at their focus and two additional GPDs filled with pressurized Ar-DME facing the sun. The Minimum Detectable Polarization is 14 % at 1 mCrab in 10E5 s (2-10 keV) and 0.6 % for an X10 class flare. The Half Energy Width, measured at PANTER X-ray test facility (MPE, Germany) with JET-X optics is 24 arcsec. XIPE takes advantage of a low-earth equatorial orbit with Malindi as down-link station and of a Mission Operation Center (MOC) at INPE (Brazil).Comment: 49 pages, 14 figures, 6 tables. Paper published in Experimental Astronomy http://link.springer.com/journal/1068

Six versus 12 months' adjuvant trastuzumab in patients with HER2-positive early breast cancer: the PERSEPHONE non-inferiority RCT

Background The addition of adjuvant trastuzumab to chemotherapy has significantly improved outcomes in human epidermal growth factor receptor 2 (HER2) positive early, potentially curable breast cancer. Twelve months’ trastuzumab tested in the registration trials was adopted for standard adjuvant treatment in 2006. Subsequently similar outcomes were demonstrated using 9 weeks trastuzumab. Shorter durations were therefore tested for non-inferiority. Objectives To establish whether 6 months’ adjuvant trastuzumab is non-inferior to 12 months in HER2-positive early breast cancer using a primary endpoint of 4-year disease-free-survival (DFS). Design Phase III randomised, controlled, non-inferiority trial. Setting 152 NHS Hospitals. Participants 4088 patients with HER2-positive early breast cancer planned to receive both chemotherapy and trastuzumab. Intervention Randomisation (1:1) between six months’ or twelve months’ trastuzumab. Main outcomes Primary endpoint was DFS four years after diagnosis. Secondary endpoints were overall survival (OS), cost effectiveness, and cardiac function during trastuzumab. Assuming a 4-year DFS rate of 80% with 12 months, 4000 patients were required to demonstrate non-inferiority of 6-months (5% 1-sided significance, 85% power), defining the non-inferiority limit as no worse than 3% below the standard arm. Costs and quality-adjusted life years (QALYs) were estimated by within-trial analysis and a lifetime decision-analytic model. Results Between 4th October 2007 and 31st July 2015, 2045 patients were randomised to 12-months’ trastuzumab and 2043 to 6-months. Sixty-nine percent had ER-positive disease; 90% received anthracyclines (49% with taxanes; 41% without taxanes); 10% received taxanes without anthracyclines; 54% had trastuzumab sequentially after chemotherapy; 85% received adjuvant chemotherapy (58% were node negative). At 6.1 years median follow-up with 389 (10%) deaths, and 566 (14%) DFS events, 4-year DFS rates for the 4088 patients were 89.5% (95% CI, 88.1-90.8) in the 6-month group and 90.3% (95% CI 88.9- 91.5) in the 12-month group (Hazard Ratio 1.10; 90% CI 0.96–1.26, non-inferiority p=0.01), demonstrating non-inferiority of 6-months’ trastuzumab. Congruent results were found for OS (non-inferiority p=0.0003), and landmark analyses 6 months from starting trastuzumab (non-inferiority p=0.03 (DFS) and p=0.006 (OS)). 6-months’ trastuzumab resulted in fewer patients reporting adverse events of severe grade (365/1929 (19%) versus 460/1935 (24%) 12-month patients, p=0.0003) or stopping early because of cardiotoxicity (61/1977 (3%) versus 146/1941 (8%) 12-month patients, p<0.0001). Health economic analysis showed significantly lower lifetime costs and similar lifetime QALYs, and thus a high probability that 6 months is cost-effective compared to 12 months. Patient reported experiences on the trial highlighted fatigue, and aches and pains most frequently. Limitations The type of chemotherapy and timing of trastuzumab changed through the recruitment phase of the study as standard practice altered. Conclusions PERSEPHONE demonstrated that in HER2-positive early breast cancer 6 months’ adjuvant trastuzumab was non-inferior to 12 months. There was significantly less cardiac toxicity and fewer severe adverse events with 6 months’ treatment. Future work On-going translational work investigates patient and tumour genetic determinants of toxicity, and trastuzumab efficacy. An individual patient data meta-analysis with PHARE and other trastuzumab duration trials is planned. Trial registration ISRCTN 52968807 Funding National Institute for Health Research, Health Technology Assessment Programme (HTA Project: 06/303/98).National Institute for Health Research, Health Technology Assessment Programme (HTA Project: 06/303/98)

Coal-derived rates of atmospheric dust deposition during the Permian

Despite widespread evidence for atmospheric dust deposition prior to the Quaternary, quantitative rate data remains sparse. As dust influences both climate and biological productivity, the absence of quantitative dust data limits the comprehensiveness of models of pre-Quaternary climate and biogeochemical cycles. Here, we propose that inorganic matter contained in coal primarily records atmospheric dust deposition. To test this, we use the average concentration of inorganic matter in Permian coal to map global patterns and deposition rates of atmospheric dust over Pangea. The dust accumulation rate is calculated assuming Permian peat carbon accumulation rates in temperate climates were similar to Holocene rates and accounting for the loss of carbon during coalification. Coal-derived rates vary from 0.02 to 25 g m− 2 year− 1, values that fall within the present-day global range. A well-constrained East–West pattern of dust deposition corresponding to expected palaeoclimate gradients extends across Gondwana with maximum dust deposition rates occurring close to arid regions. A similar pattern is partially defined over the northern hemisphere. Patterns are consistent with the presence of two large global dust plumes centred on the tropics. The spatial patterns of dust deposition were also compared to dust cycle simulations for the Permian made with the Community Climate System Model version 3 (CCSM3). Key differences between the simulations and the coal data are the lack of evidence for an Antarctic dust source, higher than expected dust deposition over N and S China and greater dust deposition rates over Western Gondwana. This new coal-based dust accumulation rate data expands the pre-Neogene quantitative record of atmospheric dust and can help to inform and validate models of global circulation and biogeochemical cycles over the past 350 Myr

Masses, radii, and orbits of small Kepler planets : The transition from gaseous to rocky planets

We report on the masses, sizes, and orbits of the planets orbiting 22 Kepler stars. There are 49 planet candidates around these stars, including 42 detected through transits and 7 revealed by precise Doppler measurements of the host stars. Based on an analysis of the Kepler brightness measurements, along with high-resolution imaging and spectroscopy, Doppler spectroscopy, and (for 11 stars) asteroseismology, we establish low false-positive probabilities (FPPs) for all of the transiting planets (41 of 42 have an FPP under 1%), and we constrain their sizes and masses. Most of the transiting planets are smaller than three times the size of Earth. For 16 planets, the Doppler signal was securely detected, providing a direct measurement of the planet's mass. For the other 26 planets we provide either marginal mass measurements or upper limits to their masses and densities; in many cases we can rule out a rocky composition. We identify six planets with densities above 5 g cm-3, suggesting a mostly rocky interior for them. Indeed, the only planets that are compatible with a purely rocky composition are smaller than 2 R ⊕. Larger planets evidently contain a larger fraction of low-density material (H, He, and H2O).Peer reviewedFinal Accepted Versio