The influence of MRI scan position on patients with oropharyngeal cancer undergoing radical radiotherapy

<p>Background: The purpose of this study was to demonstrate how magnetic resonance imaging (MRI) patient position protocols influence registration quality in patients with oropharyngeal cancer undergoing radical radiotherapy and the consequences for gross tumour volume (GTV) definition and radiotherapy planning.</p> <p>Methods and materials: Twenty-two oropharyngeal patients underwent a computed tomography (CT), a diagnostic MRI (MRID) and an MRI in the radiotherapy position within an immobilization mask (MRIRT). Clinicians delineated the GTV on the CT viewing the MRID separately (GTVC); on the CT registered to MRID (GTVD) and on the CT registered to MRIRT (GTVRT). Planning target volumes (PTVs) were denoted similarly. Registration quality was assessed by measuring disparity between structures in the three set-ups. Volumetric modulated arc therapy (VMAT) radiotherapy planning was performed for PTVC, PTVD and PTVRT. To determine the dose received by the reference PTVRT, we optimized for PTVC and PTVD while calculating the dose to PTVRT. Statistical significance was determined using the two-tailed Mann–Whitney or two-tailed paired student t-tests.</p> <p>Results: A significant improvement in registration accuracy was found between CT and MRIRT versus the MRID measuring distances from the centre of structures (geometric mean error of 2.2 mm versus 6.6 mm). The mean GTVC (44.1 cm3) was significantly larger than GTVD (33.7 cm3, p value = 0.027) or GTVRT (30.5 cm3, p value = 0.014). When optimizing the VMAT plans for PTVC and investigating the mean dose to PTVRT neither the dose to 99% (58.8%) nor 95% of the PTV (84.7%) were found to meet the required clinical dose constraints of 90% and 95% respectively. Similarly, when optimizing for PTVD the mean dose to PTVRT did not meet clinical dose constraints for 99% (14.9%) nor 95% of the PTV (66.2%). Only by optimizing for PTVRT were all clinical dose constraints achieved.</p> <p>Conclusions: When oropharyngeal patients MRI scans are performed in the radiotherapy position there are significant improvements in CT-MR image registration, target definition and PTV dose coverage.</p&gt

A study of the boundary flow in a rocket combustion chamber. Part 2 - Data analysis, correlation, and theoretical prediction Final report

Processing data on heat flux and chemical composition in rocket combustion chamber boundary flow - table

Study of diffusion weighted MRI as a predictive biomarker of response during radiotherapy for high and intermediate risk squamous cell cancer of the oropharynx: The MeRInO study

Introduction and background: A significant proportion of patients with intermediate and high risk squamous cell cancer of the oropharynx (OPSCC) continue to relapse locally despite radical chemoradiotherapy (CRT). The toxicity of the current combination of intensified dose per fraction radiotherapy and platinum based chemotherapy limits further uniform intensification. If a predictive biomarker for outcomes from CRT can be identified during treatment then individualised and adaptive treatment strategies may be employed. Methods/design: The MeRInO study is a prospective observational imaging study of patients with intermediate and high risk, locally advanced OPSCC receiving radical RT or concurrent CRT Patients undergo diffusion weighted MRI prior to treatment (MRI_1) and during the third week of RT (MRI_2). Apparent diffusion coefficient (ADC) measurements will be made on each scan for previously specified target lesions (primary and lymph nodes) and change in ADC calculated. Patients will be followed up and disease status for each target lesion noted. The primary aim of the MeRInO study is to determine the threshold change in ADC from baseline to week 3 of RT that may identify the sub-group of non-responders during treatment. Discussion: The use of DW-MRI as a predictive biomarker during RT for SCC H&N is in its infancy but studies to date have found that response to treatment may indeed be predicted by comparison of DW-MRI carried out before and during treatment. However, previous studies have included all sub-sites and biological sub-types. Establishing ADC thresholds that predict for local failure is an essential step towards using DW-MRI to improve the therapeutic ratio in treating SCC H&N. This would be done most robustly in a specific H&N sub-site and in sub-types with similar biological behaviour. The MeRInO study will help establish these thresholds in OPSCC

Developing awareness of sustainability in nursing and midwifery using a scenario-based approach: Evidence from a pre and post educational intervention study

publisher: Elsevier articletitle: Developing awareness of sustainability in nursing and midwifery using a scenario-based approach: Evidence from a pre and post educational intervention study journaltitle: Nurse Education Today articlelink: http://dx.doi.org/10.1016/j.nedt.2017.04.022 content_type: article copyright: © 2017 Published by Elsevier Ltd

Exclusive W + photon production in proton-antiproton collisions I: general formalism

We present a detailed computation of the fully exclusive cross section of p + antip --> W + photon + X with X = 0 and 1 jet in the framework of the factorization theorem and dimensional regularization. Order alpha-strong and photon bremsstrahlung contributions are discussed in the MS-bar mass factorization scheme. The resulting expressions are ready to be implemented numerically using Monte Carlo techniques to compute single and double differential cross sections and correlations between outgoing pairs of particles.Comment: ITP-SB-93-72, 40 pages, LateX. 3*4 figures in separate file. ([email protected]) ([email protected]

Polar ozone

The observation and interpretation of a large, unexpected ozone depletion over Antarctica has changed the international scientific view of stratospheric chemistry. The observations which show the veracity, seasonal nature, and vertical structure of the Antarctic ozone hole are presented. Evidence for Arctic and midlatitude ozone loss is also discussed. The chemical theory for Antarctic ozone depletion centers around the occurrence of polar stratospheric clouds (PSCs) in Antarctic winter and spring; the climatology and radiative properties of these clouds are presented. Lab studies of the physical properties of PSCs and the chemical processes that subsequently influence ozone depletion are discussed. Observations and interpretation of the chemical composition of the Antarctic stratosphere are described. It is shown that the observed, greatly enhanced abundances of chlorine monoxide in the lower stratosphere are sufficient to explain much if not all of the ozone decrease. The dynamic meteorology of both polar regions is given, interannual and interhemispheric variations in dynamical processes are outlined, and their likely roles in ozone loss are discussed

Identification of Burkholderia mallei and Burkholderia pseudomallei adhesins for human respiratory epithelial cells

<p>Abstract</p> <p>Background</p> <p><it>Burkholderia pseudomallei </it>and <it>Burkholderia mallei </it>cause the diseases melioidosis and glanders, respectively. A well-studied aspect of pathogenesis by these closely-related bacteria is their ability to invade and multiply within eukaryotic cells. In contrast, the means by which <it>B. pseudomallei </it>and <it>B. mallei </it>adhere to cells are poorly defined. The purpose of this study was to identify adherence factors expressed by these organisms.</p> <p>Results</p> <p>Comparative sequence analyses identified a gene product in the published genome of <it>B. mallei </it>strain ATCC23344 (locus # BMAA0649) that resembles the well-characterized <it>Yersinia enterocolitica </it>autotransporter adhesin YadA. The gene encoding this <it>B. mallei </it>protein, designated <it>boaA</it>, was expressed in <it>Escherichia coli </it>and shown to significantly increase adherence to human epithelial cell lines, specifically HEp2 (laryngeal cells) and A549 (type II pneumocytes), as well as to cultures of normal human bronchial epithelium (NHBE). Consistent with these findings, disruption of the <it>boaA </it>gene in <it>B. mallei </it>ATCC23344 reduced adherence to all three cell types by ~50%. The genomes of the <it>B. pseudomallei </it>strains K96243 and DD503 were also found to contain <it>boaA </it>and inactivation of the gene in DD503 considerably decreased binding to monolayers of HEp2 and A549 cells and to NHBE cultures.</p> <p>A second YadA-like gene product highly similar to BoaA (65% identity) was identified in the published genomic sequence of <it>B. pseudomallei </it>strain K96243 (locus # BPSL1705). The gene specifying this protein, termed <it>boaB</it>, appears to be <it>B. pseudomallei</it>-specific. Quantitative attachment assays demonstrated that recombinant <it>E. coli </it>expressing BoaB displayed greater binding to A549 pneumocytes, HEp2 cells and NHBE cultures. Moreover, a <it>boaB </it>mutant of <it>B. pseudomallei </it>DD503 showed decreased adherence to these respiratory cells. Additionally, a <it>B. pseudomallei </it>strain lacking expression of both <it>boaA </it>and <it>boaB </it>was impaired in its ability to thrive inside J774A.1 murine macrophages, suggesting a possible role for these proteins in survival within professional phagocytic cells.</p> <p>Conclusions</p> <p>The <it>boaA </it>and <it>boaB </it>genes specify adhesins that mediate adherence to epithelial cells of the human respiratory tract. The <it>boaA </it>gene product is shared by <it>B. pseudomallei </it>and <it>B. mallei </it>whereas BoaB appears to be a <it>B. pseudomallei</it>-specific adherence factor.</p

Applicability constraints of the Equivalence Theorem

In this work we study the applicability of the Equivalence Theorem, either for unitary models or within an effective lagrangian approach. There are two types of limitations: the existence of a validity energy window and the use of the lowest order in the electroweak constants. For the first kind, we consider some methods, based on dispersion theory or the large $N$ limit, that allow us to extend the applicability. For the second, we have obtained numerical estimates of the effect of neglecting higher orders in the perturbative expansion.Comment: Final version to appear in Phys. Rev. D. Power counting and energy range estimates have been refined, improved referencing. 4 postscript figures, uses revtex. FT-UCM 1/9

High-resolution projections of surface water availability for Tasmania, Australia

Changes to streamflows caused by climate change may have major impacts on the management of water for hydro-electricity generation and agriculture in Tasmania, Australia. We describe changes to Tasmanian surface water availability from 1961–1990 to 2070–2099 using high-resolution simulations. Six fine-scale (&amp;sim;10 km&lt;sup&gt;2&lt;/sup&gt;) simulations of daily rainfall and potential evapotranspiration are generated with the CSIRO Conformal Cubic Atmospheric Model (CCAM), a variable-resolution regional climate model (RCM). These variables are bias-corrected with quantile mapping and used as direct inputs to the hydrological models AWBM, IHACRES, Sacramento, SIMHYD and SMAR-G to project streamflows. &lt;br&gt;&lt;br&gt; The performance of the hydrological models is assessed against 86 streamflow gauges across Tasmania. The SIMHYD model is the least biased (median bias = −3%) while IHACRES has the largest bias (median bias = −22%). We find the hydrological models that best simulate observed streamflows produce similar streamflow projections. &lt;br&gt;&lt;br&gt; There is much greater variation in projections between RCM simulations than between hydrological models. Marked decreases of up to 30% are projected for annual runoff in central Tasmania, while runoff is generally projected to increase in the east. Daily streamflow variability is projected to increase for most of Tasmania, consistent with increases in rainfall intensity. Inter-annual variability of streamflows is projected to increase across most of Tasmania. &lt;br&gt;&lt;br&gt; This is the first major Australian study to use high-resolution bias-corrected rainfall and potential evapotranspiration projections as direct inputs to hydrological models. Our study shows that these simulations are capable of producing realistic streamflows, allowing for increased confidence in assessing future changes to surface water variability