1,144 research outputs found

    On traces for H(curl,Ω) in Lipschitz domains

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    AbstractWe study tangential vector fields on the boundary of a bounded Lipschitz domain Ω in R3. Our attention is focused on the definition of suitable Hilbert spaces corresponding to fractional Sobolev regularities and also on the construction of tangential differential operators on the non-smooth manifold. The theory is applied to the characterization of tangential traces for the space H(curl,Ω). Hodge decompositions are provided for the corresponding trace spaces, and an integration by parts formula is proved

    Skilful prediction of Sahel summer rainfall on inter-annual and multi-year timescales

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    This is the final version of the article. Available from Springer Nature via the DOI in this record.Summer rainfall in the Sahel region of Africa exhibits one of the largest signals of climatic variability and with a population reliant on agricultural productivity, the Sahel is particularly vulnerable to major droughts such as occurred in the 1970s and 1980s. Rainfall levels have subsequently recovered, but future projections remain uncertain. Here we show that Sahel rainfall is skilfully predicted on inter-annual and multi-year (that is, >5 years) timescales and use these predictions to better understand the driving mechanisms. Moisture budget analysis indicates that on multi-year timescales, a warmer north Atlantic and Mediterranean enhance Sahel rainfall through increased meridional convergence of low-level, externally sourced moisture. In contrast, year-to-year rainfall levels are largely determined by the recycling rate of local moisture, regulated by planetary circulation patterns associated with the El Niño-Southern Oscillation. Our findings aid improved understanding and forecasting of Sahel drought, paramount for successful adaptation strategies in a changing climate.This work was supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101) and the EU FP7 SPECS project. The contribution of D.P.R. has received funding from the NERC/DFID Future Climate for Africa programme under the AMMA-2050 project, grant number NE/M019977/1

    A programme for the prevention of post-traumatic stress disorder in midwifery (POPPY): indications of effectiveness from a feasibility study

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    Background: Midwives can experience events they perceive as traumatic when providingcare. As a result, some will develop post-traumatic stress disorder (PTSD), with adverse implications for their mental health, the quality of care provided for women and the employing organizations. POPPY (Programme for the prevention of PTSD in midwifery) is a package of educational and supportive resources comprising an educational workshop, information leaflet, peer support and access to trauma-focused clinical psychology intervention. A feasibility study of POPPY implementation was completed. Objective: This study aimed to identify potential impacts of POPPY on midwives’ understandingof trauma, their psychological well-being and job satisfaction. Method: POPPY was implemented in one hospital site. Before taking part in the POPPY workshop (T1) midwives (N = 153) completed self-report questionnaires, which measured exposure to work-related trauma, knowledge and confidence of managing trauma responses, professional impacts, symptoms of PTSD, burnout and job satisfaction. Measures were repeated (T2) approximately 6 months after training (n = 91, 62%). Results: Midwives’ confidence in recognizing (p = .001) and managing early traumaresponses in themselves and their colleagues significantly improved (both p < .001). There was a trend towards reduced levels of PTSD symptomatology, and fewer midwives reported sub clinical levels of PTSD (from 10% at T1 to 7% at T2). The proportion of midwives reporting high and moderate levels of depersonalization towards care was reduced (33% to 20%) and midwives reported significantly higher levels of job satisfaction at T2 (p < .001). Reductions in self-reported stress-related absenteeism (12% to 5%), long-term changes to clinical allocation (10% to 5%) and considerations about leaving midwifery (34% to 27%) were identified. Conclusions: In conclusion, POPPY shows very positive potential to improve midwives’ mental health and the sensitivity of care they provide, and reduce service disruption and costs for trusts. Large-scale longitudinal evaluation is required

    GASP II. A MUSE view of extreme ram-pressure stripping along the line of sight: kinematics of the jellyfish galaxy JO201

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    This paper presents a spatially-resolved kinematic study of the jellyfish galaxy JO201, one of the most spectacular cases of ram-pressure stripping (RPS) in the GASP (GAs Stripping Phenomena in Galaxies with MUSE) survey. By studying the environment of JO201, we find that it is moving through the dense intra-cluster medium of Abell 85 at supersonic speeds along our line of sight, and that it is likely accompanied by a small group of galaxies. Given the density of the intra-cluster medium and the galaxy's mass, projected position and velocity within the cluster, we estimate that JO201 must so far have lost ~50% of its gas during infall via RPS. The MUSE data indeed reveal a smooth stellar disk, accompanied by large projected tails of ionised (Halpha) gas, composed of kinematically cold (velocity dispersion <40km/s) star-forming knots and very warm (>100km/s) diffuse emission which extend out to at least ~50 kpc from the galaxy centre. The ionised Halpha-emitting gas in the disk rotates with the stars out to ~6 kpc but in the disk outskirts becomes increasingly redshifted with respect to the (undisturbed) stellar disk. The observed disturbances are consistent with the presence of gas trailing behind the stellar component, resulting from intense face-on RPS happening along the line of sight. Our kinematic analysis is consistent with the estimated fraction of lost gas, and reveals that stripping of the disk happens outside-in, causing shock heating and gas compression in the stripped tails.Comment: ApJ, revised version after referee comments, 15 pages, 16 figures. The interactive version of Figure 9 can be viewed at web.oapd.inaf.it/gasp/publications.htm

    Constitutively Activated PI3K Accelerates Tumor Initiation and Modifies Histopathology of Breast Cancer

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    The gene encoding phosphatidylinositol 3-kinase catalytic subunit α-isoform (PIK3CA, p110α) is frequently activated by mutation in human cancers. Based on detection in some breast cancer precursors, PIK3CA mutations have been proposed to have a role in tumor initiation. To investigate this hypothesis, we generated a novel mouse model with a Cre-recombinase regulated allele of p110α (myristoylated-p110α, myr-p110α) along with p53fl/fl deletion and KrasG12D also regulated by Cre-recombinase. After instillation of adenovirus-expressing Cre-recombinase into mammary ducts, we found that myr-p110α accelerated breast tumor initiation in a copy number-dependent manner. Breast tumors induced by p53fl/fl;KrasG12D with no or one copy of myr-p110α had predominantly sarcomatoid features, whereas two copies of myr-p110α resulted in tumors with a carcinoma phenotype. This novel model provides experimental support for importance of active p110α in breast tumor initiation, and shows that the amount of PI3K activity can affect the rate of tumor initiation and modify the histological phenotype of breast cancer

    Effect of Impurity Scattering on the Nonlinear Microwave Response in High-Tc Superconductors

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    We theoretically investigate intermodulation distortion in high-Tc superconductors. We study the effect of nonmagnetic impurities on the real and imaginary parts of nonlinear conductivity. The nonlinear conductivity is proportional to the inverse of temperature owing to the dependence of the damping effect on energy, which arises from the phase shift deviating from the unitary limit. It is shown that the final-states interaction makes the real part predominant over the imaginary part. These effects have not been included in previous theories based on the two-fluid model, enabling a consistent explanation for the experiments with the rf and dc fields

    Modification of turbulent dissipation rates by a deep Southern Ocean eddy

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    The impact of a mesoscale eddy on the magnitude and spatial distribution of diapycnal ocean mixing is investigated using a set of hydrographic and microstructure measurements collected in the Southern Ocean. These data sampled a baroclinic, mid-depth eddy formed during the disintegration of a deep boundary current. Turbulent dissipation is suppressed within the eddy, but is elevated by up to an order of magnitude along the upper and lower eddy boundaries. A ray-tracing approximation is employed asa heuristic device to elucidate how the internal wave field evolves in the ambient velocity and stratification conditions accompanying the eddy. These calculations are consistent with the observations, suggesting reflection of internal wave energy from the eddy center and enhanced breaking through critical layer processes along the eddy boundaries. These results have important implications for understanding where and how internal wave energy is dissipated in the presence of energetic deep geostrophic flows

    Proteome Profiling of Breast Tumors by Gel Electrophoresis and Nanoscale Electrospray Ionization Mass Spectrometry

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    We have conducted proteome-wide analysis of fresh surgery specimens derived from breast cancer patients, using an approach that integrates size-based intact protein fractionation, nanoscale liquid separation of peptides, electrospray ion trap mass spectrometry, and bioinformatics. Through this approach, we have acquired a large amount of peptide fragmentation spectra from size-resolved fractions of the proteomes of several breast tumors, tissue peripheral to the tumor, and samples from patients undergoing noncancer surgery. Label-free quantitation was used to generate protein abundance maps for each proteome and perform comparative analyses. The mass spectrometry data revealed distinct qualitative and quantitative patterns distinguishing the tumors from healthy tissue as well as differences between metastatic and non-metastatic human breast cancers including many established and potential novel candidate protein biomarkers. Selected proteins were evaluated by Western blotting using tumors grouped according to histological grade, size, and receptor expression but differing in nodal status. Immunohistochemical analysis of a wide panel of breast tumors was conducted to assess expression in different types of breast cancers and the cellular distribution of the candidate proteins. These experiments provided further insights and an independent validation of the data obtained by mass spectrometry and revealed the potential of this approach for establishing multimodal markers for early metastasis, therapy outcomes, prognosis, and diagnosis in the future. © 2008 American Chemical Society

    'Treatment of the Sportsman's groin': British Hernia Society's 2014 position statement based on the Manchester Consensus Conference

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    &lt;b&gt;Introduction&lt;/b&gt; The aim was to produce a multidisciplinary consensus to determine the current position on the nomenclature, definition, diagnosis, imaging modalities and management of Sportsman's groin (SG).&lt;p&gt;&lt;/p&gt; &lt;b&gt;Methods&lt;/b&gt; Experts in the diagnosis and management of SG were invited to participate in a consensus conference held by the British Hernia Society in Manchester, UK on 11–12 October 2012. Experts included a physiotherapist, a musculoskeletal radiologist and surgeons with a proven track record of expertise in this field. Presentations detailing scientific as well as outcome data from their own experiences were given. Records were made of the presentations with specific areas debated openly.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Results&lt;/b&gt; The term ‘inguinal disruption’ (ID) was agreed as the preferred nomenclature with the term ‘Sportsman's hernia’ or ‘groin’ rejected, as no true hernia exists. There was an overwhelming agreement of opinion that there was abnormal tension in the groin, particularly around the inguinal ligament attachment. Other common findings included the possibility of external oblique disruption with consequent small tears noted as well as some oedema of the tissues. A multidisciplinary approach with tailored physiotherapy as the initial treatment was recommended with any surgery involving releasing the tension in the inguinal canal by various techniques and reinforcing it with a mesh or suture repair. A national registry should be developed for all athletes undergoing surgery.&lt;p&gt;&lt;/p&gt; &lt;b&gt;Conclusions&lt;/b&gt; ID is a common condition where no true hernia exists. It should be managed through a multidisciplinary approach to ensure consistent standards and outcomes are achieved

    Skilful seasonal predictions of Summer European rainfal

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    This is the author accepted manuscript. The final version is available from American Geophysical Union (AGU) via the DOI in this record.Year-to-year variability in Northern European summer rainfall has profound societal and economic impacts; however current seasonal forecast systems show no significant forecast skill. Here we show skilful predictions are possible (r~0.5, p80 members) are required for skilful predictions. This work is promising for the development of European summer rainfall climate services.This work was supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101), the EU FP7 SPECS project. We acknowledge the E-OBS dataset from the EU-FP6 project ENSEMBLES (http://ensembles-eu.metoffice.com) and the data providers in the ECA&D project (http://www.ecad.eu). We also would like to thank Gerard van der Schrier and Else Van Den Besselaar for kindly providing us the pre-release E-OBS dataset version 'v16e' and further support. Model data used to create the figures are available from the authors upon request for academic use
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