6,337 research outputs found

    Evaluation of Overall Survival (OS) and Event-Free Survival (EFS) of paediatric sarcoma patients at a single institution

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    Aims: To evaluate OS and EFS of paediatric sarcoma patients with an interest in comparing metastatic cases with non-metastatic cases, and compiling statistics on treatment methods. Methods: Information was obtained from patient notes in the Schiehallion ward. These contained information about diagnosis, treatment, prognostic indicators, and outcomes for each patient. Results: 56 patients, 2001-2008. Osteosarcoma: 11 patients, 7♂, 4♀; age range: 4-16; = 10; OS = 64%, EFS = 55%; Primary site of disease: Femur (47%), Tibia (41%), Humerus (5.5%), Scapula (5.5%), Other (1%); Metastatic Rate = 27% (OS = 0%). Ewing’s sarcoma: 24 patients, 10♂, 14♀; age range: 1-16, = 12; OS = 71%, EFS = 58%; Primary site of disease: Pelvis (29%), Femur (22%), Paraspinal (16%), Chest Wall (10%), Tibia (10%), Other (13%); Metastatic Rate = 21% (OS = 40%; EFS = 40%); Alveolar rhabdomyosarcoma: 10 patients; OS= 80%, EFS = 60%; Metastatic Rate = 20% (OS = 100%; EFS = 100%). Embryonal rhabdomyosarcoma: 11 patients; OS = 73%, EFS = 73%; Metastatic Rate = 0%. Conclusions: Our results reflect access to an experienced and innovative paediatric sarcoma service with close links to a national Sarcoma MDT. The data falls in line with other studies in terms of age of onset, location of primary tumour, metastatic rate, site of metastases, and prognosis for all cancer types. Limb salvage surgery is greatly favoured over amputation for both osteosarcoma and Ewing’s sarcoma. Females have a more favourable prognosis in osteosarcoma and a slightly poorer prognosis in Ewing’s sarcoma. Yorkhill’s overall survival rates are currently better than the UK-wide statistic for three of the four tumours examined.</p

    Quantum Dynamics of the Slow Rollover Transition in the Linear Delta Expansion

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    We apply the linear delta expansion to the quantum mechanical version of the slow rollover transition which is an important feature of inflationary models of the early universe. The method, which goes beyond the Gaussian approximation, gives results which stay close to the exact solution for longer than previous methods. It provides a promising basis for extension to a full field theoretic treatment.Comment: 12 pages, including 4 figure

    Convergence of the Optimized Delta Expansion for the Connected Vacuum Amplitude: Zero Dimensions

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    Recent proofs of the convergence of the linear delta expansion in zero and in one dimensions have been limited to the analogue of the vacuum generating functional in field theory. In zero dimensions it was shown that with an appropriate, NN-dependent, choice of an optimizing parameter \l, which is an important feature of the method, the sequence of approximants ZNZ_N tends to ZZ with an error proportional to ecN{\rm e}^{-cN}. In the present paper we establish the convergence of the linear delta expansion for the connected vacuum function W=lnZW=\ln Z. We show that with the same choice of \l the corresponding sequence WNW_N tends to WW with an error proportional to ecN{\rm e}^{-c\sqrt N}. The rate of convergence of the latter sequence is governed by the positions of the zeros of ZNZ_N.Comment: 20 pages, LaTeX, Imperial/TP/92-93/5

    Campylobacter jejuni PflB is required for motility and colonisation of the chicken gastrointestinal tract.

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    Campylobacter jejuni is the leading cause of foodborne bacterial gastroenteritis worldwide. Although the mechanisms by which C. jejuni causes disease are not completely understood, the presence of functional flagella appears to be required for colonisation of the gastrointestinal tract of humans and animals. Therefore much attention has been given to understanding the synthesis and role of flagella in C. jejuni. In this study we report insights into the function of PflB that is essential for Campylobacter motility. We have explored the function of this gene by constructing deletion mutants in C. jejuni strains NCTC11168 and M1, in the genes cj0390 and CJM1_0368, respectively. The mutants were non-motile yet assembled flagella that appeared structurally identical to the wild type. Furthermore the protein is required for C. jejuni colonisation of caeca in a two-week old chicken colonisation model.This work was supported by the Department for Environment, Food and Rural Affairs (Defra) Senior Fellowship awarded to D.J.M.This is the author accepted manuscript. The final version is available from Elsevier via http://dx.doi.org/10.1016/j.micpath.2015.09.01

    Strontium isotope stratigraphy and age estimates for the Leisey Shell Pit faunas, Hillsborough County, Florida

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    The vertebrate fauna of the Leisey Shell Pit near Tampa Bay, Florida, represents one of the more significant lrvingtonian mammalian faunas of North America. The fossil vertebrates occur in thin bone beds bounded above and below by massive shell beds containing a rich invertebrate ( chiefly molluscan) fauna. Debate has arisen concerning the precise age of the faunas at Leisey. Although generally agreed to be Pleistocene, estimates based upon vertebrate biostratigraphy suggest a somewhat older age than do estimates based upon molluscan biostratigraphy. To help resolve this controvefliy, 87Sr/86Sr ratios were determined on molluscan shells throughout the section. These ratios were then correlated to the global sea water 87Sr/86Sr curve for age detennination. The Sr isotopes support an early Pleistocene age for the vertebrate fauna and suggest a complex history for the shell accumulations

    Template banks to search for compact binaries with spinning components in gravitational wave data

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    Gravitational waves from coalescing compact binaries are one of the most promising sources for detectors such as LIGO, Virgo and GEO600. If the components of the binary posess significant angular momentum (spin), as is likely to be the case if one component is a black hole, spin-induced precession of a binary's orbital plane causes modulation of the gravitational-wave amplitude and phase. If the templates used in a matched-filter search do not accurately model these effects then the sensitivity, and hence the detection rate, will be reduced. We investigate the ability of several search pipelines to detect gravitational waves from compact binaries with spin. We use the post-Newtonian approximation to model the inspiral phase of the signal and construct two new template banks using the phenomenological waveforms of Buonanno, Chen and Vallisneri. We compare the performance of these template banks to that of banks constructed using the stationary phase approximation to the non-spinning post-Newtonian inspiral waveform currently used by LIGO and Virgo in the search for compact binary coalescence. We find that, at the same false alarm rate, a search pipeline using phenomenological templates is no more effective than a pipeline which uses non-spinning templates. We recommend the continued use of the non-spinning stationary phase template bank until the false alarm rate associated with templates which include spin effects can be substantially reduced.Comment: 11 pages, 3 figure

    Polarized radio emission over the southern Galactic plane at 2.4 GHz

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    Polarimetric results from the Parkes 2.4-GHz survey of the southern Galactic plane are presented. These take the form of a series of images, detailing the polarized intensity and vector position angles over the survey area. The observations were made using the 64-m Parkes radio telescope, and cover the Galactic plane within the region 238°≤l≤5°, with a latitude range of at least |b|≤5°, with some coverage to b = +7° and b = -8°. The resolution of the images is 10.4 arcmin. The rms noise of the polarized intensity images is 11 mJy beam area-1 (5.3 mK), and the rms variation in the vector position angles is of the order of several dgrees. The images show many polarized structures, over a wide range of intensities and angular sizes. Bright, extended regions of polarized emission (of the order of 5° across) are detected, including the Vela supernova remnant and a large 'cap' structure appearing to the north of Sgr A. A quasi-uniform 'background' component of faint, patchy emission is seen over the length of the survey. This faint component appears to originate over a range of distances, out to greater than 5 kpc, and shows considerable structure in the orientations of the polarization vectors. Several bright H II complexes are seen to exhibit bipolar, depolarizing 'plumes', several degrees in length, which are interpreted as outflows of low-density thermal material (with densities in the range 1-10 cm-3)

    The Fading Radio Emission from SN 1961V: Evidence for a Type II Peculiar Supernova?

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    Using the Very Large Array (VLA), we have detected radio emission from the site of SN 1961V in the Sc galaxy NGC 1058. With a peak flux density of 0.063 +/- 0.008 mJy/beam at 6 cm and 0.147 +/- 0.026 mJy/beam at 18 cm, the source is non-thermal, with a spectral index of -0.79 +/- 0.23. Within errors, this spectral index is the same value reported for previous VLA observations taken in 1984 and 1986. The radio emission at both wavelengths has decayed since the mid 1980's observations with power-law indices of beta(20cm) = -0.69 +/- 0.23 and beta(6cm) = -1.75 +/- 0.16. We discuss the radio properties of this source and compare them with those of Type II radio supernovae and luminous blue variables.Comment: 19 pages, 3 figures; To appear in the Astronomical Journa
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