132 research outputs found

    The effect of flowering stage in wheat on the infection efficiency of Ustilago tritici

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    Dans l'ouest du Canada, la détermination du niveau de résistance de lignées de blé (Triticum aestivum) à l’ Ustiiago tritici est habituellement faite par inoculation lorsque les plantes atteignent le stade mi-anthèse du développement de l'épi. Par contre, il n'est pas toujours possible de faire les inoculations à ce stade, ainsi des inoculations sont parfois faites quelques jours avant ou après la mi-anthèse. L'objectif de cette étude était de déterminer si l'inoculation, par la méthode du vide partiel, d'épis de blé avec l’U. tritici à différents stades du développement de l'épi pouvait avoir un effet sur le nombre de grains viables par épi et, ultérieurement, sur le pourcentage de plantes cariées issues de grains inoculés. À chaque année durant 5 ans, quatre lignées de blé ont été inoculées au champ à trois différents stades du développement de l'épi. Les stades du développement de l'épi étudiés étaient la pré-anthèse, la mi-anthèse (les anthères à chaque extrémité de l'épi sont déhiscentes alors que celles du centre sont jaunes) et la post-anthèse (toutes les anthères sont déhiscentes). Il y avait des différences significatives entre les quatre lignées de blé et les 5 années de l'étude quant au nombre de grains viables par épi et le pourcentage de plantes cariées. Un nombre de grains viables par épi plus grand et un pourcentage plus faible de plantes cariées ont été significativement obtenus avec l'inoculation post-anthèse. Nous concluons que l'inoculation de l’Ustilago tritici par la méthode du vide partiel doit être faite au stade préanthèse ou mi-anthèse du développement de l'épi de blé afin de minimiser les effets négatifs de la maturité sur l'efficacité d'infection.In general, in western Canada, the inoculation of wheat (Triticum aestivum) lines to determine the level of resistance to Ustiiago tritici occurs when the plants are at the mid-anthesis stage of spike development. However, it is not always possible to inoculate at this stage so occasionally inoculations are done a few days before or after mid-anthesis. The objective of this study was to determine if inoculation of wheat spikes with U. tritici at different stages of spike development using the partial-vacuum method affected the number of viable seed per spike and subsequent percentage of smutted plants grown from inoculated seed. Four lines of wheat were inoculated at three different stages of spike development in the field each year for 5 years. The stages of spike development studied were preanthesis, mid-anthesis (anthers at either end of the spike were dehisced while those in the middle of the spike were yellow), and post-anthesis (all anthers dehisced). There were significant differences among the four wheat lines and the 5 years of the study for the number of viable seed per spike and the percent of smutted plants. Inoculation at post-anthesis resulted in a significantly greater number of viable seed per spike and lower percentage of smutted plants. We conclude that the partial-vacuum method of inoculation with Ustiiago tritici should be done at the pre- or midanthesis stage of wheat head development to minimize the negative effect of maturity on infection efficiency

    Quasi-classical Lie algebras and their contractions

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    After classifying indecomposable quasi-classical Lie algebras in low dimension, and showing the existence of non-reductive stable quasi-classical Lie algebras, we focus on the problem of obtaining sufficient conditions for a quasi-classical Lie algebras to be the contraction of another quasi-classical algebra. It is illustrated how this allows to recover the Yang-Mills equations of a contraction by a limiting process, and how the contractions of an algebra may generate a parameterized families of Lagrangians for pairwise non-isomorphic Lie algebras.Comment: 17 pages, 2 Table

    A feasibility randomized controlled trial of a guided workbook intervention to support work-related goals among cancer survivors in the UK

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    Objectives: Employment following illness is associated with better physical and psychological functioning. This study aimed to assess the feasibility and acceptability of a theoretically-led workbook intervention designed to support cancer patients returning to work. Design: Parallel-group randomized controlled trial with embedded qualitative interviews Setting: Oncology clinics within four English National Health Service Trusts Participants: Patients who had received a diagnosis of breast, gynecological, prostate or colorectal cancer and who were at least 2 weeks post-treatment initiation. Intervention: A self-guided WorkPlan workbook designed to support cancer patients to return to work with fortnightly telephone support calls to discuss progress. The control group received treatment as usual, and were offered the workbook at the end of their 12-month follow-up. Outcome measures: We assessed aspects of feasibility including eligibility, recruitment, data collection, attrition, feasibility of the methodology, acceptability of the intervention and potential to calculate cost-effectiveness. Results: The recruitment rate of eligible patients was 44%; 68 participants consented and 58 (85%) completed baseline measures. Randomization procedures were acceptable, data collection methods (including cost-effectiveness data) were feasible and the intervention was acceptable to participants. Retention rates at six and 12 months follow-up were 72% and 69% respectively. At 6-month follow-up 30% of the usual care group had returned to full or part-time work (including phased return to work) compared to 43% of the intervention group. At 12-months the percentages were 47% (usual care) and 68% (intervention). Conclusions: The findings confirm the feasibility of a definitive trial, although further consideration needs to be given to increasing the participation rates among men and Black and ethnic minority patients diagnosed with cancer

    Status of the UCNτ experiment

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    The neutron is the simplest nuclear system that can be used to probe the structure of the weak interaction and search for physics beyond the standard model. Measurements of neutron lifetime and β-decay correlation coefficients with precisions of 0.02% and 0.1%, respectively, would allow for stringent constraints on new physics. The UCNτ experiment uses an asymmetric magneto-gravitational UCN trap with in situ counting of surviving neutrons to measure the neutron lifetime, τ_n = 877.7s (0.7s)_(stat) (+0.4/−0.2s)_(sys). We discuss the recent result from UCNτ, the status of ongoing data collection and analysis, and the path toward a 0.25 s measurement of the neutron lifetime with UCNτ

    An Observational Overview of Solar Flares

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    We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities, the article is split into topical sections which deal with different areas of flare phenomena (footpoints and ribbons, coronal sources, relationship to coronal mass ejections) and their interconnections. We also discuss flare soft X-ray spectroscopy and the energetics of the process. The emphasis is to describe the observations from multiple points of view, while bearing in mind the models that link them to each other and to theory. The present theoretical and observational understanding of solar flares is far from complete, so we conclude with a brief discussion of models, and a list of missing but important observations.Comment: This is an article for a monograph on the physics of solar flares, inspired by RHESSI observations. The individual articles are to appear in Space Science Reviews (2011

    Global surveillance of cancer survival 1995-2009: analysis of individual data for 25,676,887 patients from 279 population-based registries in 67 countries (CONCORD-2)

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    BACKGROUND: Worldwide data for cancer survival are scarce. We aimed to initiate worldwide surveillance of cancer survival by central analysis of population-based registry data, as a metric of the effectiveness of health systems, and to inform global policy on cancer control. METHODS: Individual tumour records were submitted by 279 population-based cancer registries in 67 countries for 25·7 million adults (age 15-99 years) and 75,000 children (age 0-14 years) diagnosed with cancer during 1995-2009 and followed up to Dec 31, 2009, or later. We looked at cancers of the stomach, colon, rectum, liver, lung, breast (women), cervix, ovary, and prostate in adults, and adult and childhood leukaemia. Standardised quality control procedures were applied; errors were corrected by the registry concerned. We estimated 5-year net survival, adjusted for background mortality in every country or region by age (single year), sex, and calendar year, and by race or ethnic origin in some countries. Estimates were age-standardised with the International Cancer Survival Standard weights. FINDINGS: 5-year survival from colon, rectal, and breast cancers has increased steadily in most developed countries. For patients diagnosed during 2005-09, survival for colon and rectal cancer reached 60% or more in 22 countries around the world; for breast cancer, 5-year survival rose to 85% or higher in 17 countries worldwide. Liver and lung cancer remain lethal in all nations: for both cancers, 5-year survival is below 20% everywhere in Europe, in the range 15-19% in North America, and as low as 7-9% in Mongolia and Thailand. Striking rises in 5-year survival from prostate cancer have occurred in many countries: survival rose by 10-20% between 1995-99 and 2005-09 in 22 countries in South America, Asia, and Europe, but survival still varies widely around the world, from less than 60% in Bulgaria and Thailand to 95% or more in Brazil, Puerto Rico, and the USA. For cervical cancer, national estimates of 5-year survival range from less than 50% to more than 70%; regional variations are much wider, and improvements between 1995-99 and 2005-09 have generally been slight. For women diagnosed with ovarian cancer in 2005-09, 5-year survival was 40% or higher only in Ecuador, the USA, and 17 countries in Asia and Europe. 5-year survival for stomach cancer in 2005-09 was high (54-58%) in Japan and South Korea, compared with less than 40% in other countries. By contrast, 5-year survival from adult leukaemia in Japan and South Korea (18-23%) is lower than in most other countries. 5-year survival from childhood acute lymphoblastic leukaemia is less than 60% in several countries, but as high as 90% in Canada and four European countries, which suggests major deficiencies in the management of a largely curable disease. INTERPRETATION: International comparison of survival trends reveals very wide differences that are likely to be attributable to differences in access to early diagnosis and optimum treatment. Continuous worldwide surveillance of cancer survival should become an indispensable source of information for cancer patients and researchers and a stimulus for politicians to improve health policy and health-care systems

    A novel formulation of inhaled sodium cromoglicate (PA101) in idiopathic pulmonary fibrosis and chronic cough: a randomised, double-blind, proof-of-concept, phase 2 trial

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    Background Cough can be a debilitating symptom of idiopathic pulmonary fibrosis (IPF) and is difficult to treat. PA101 is a novel formulation of sodium cromoglicate delivered via a high-efficiency eFlow nebuliser that achieves significantly higher drug deposition in the lung compared with the existing formulations. We aimed to test the efficacy and safety of inhaled PA101 in patients with IPF and chronic cough and, to explore the antitussive mechanism of PA101, patients with chronic idiopathic cough (CIC) were also studied. Methods This pilot, proof-of-concept study consisted of a randomised, double-blind, placebo-controlled trial in patients with IPF and chronic cough and a parallel study of similar design in patients with CIC. Participants with IPF and chronic cough recruited from seven centres in the UK and the Netherlands were randomly assigned (1:1, using a computer-generated randomisation schedule) by site staff to receive PA101 (40 mg) or matching placebo three times a day via oral inhalation for 2 weeks, followed by a 2 week washout, and then crossed over to the other arm. Study participants, investigators, study staff, and the sponsor were masked to group assignment until all participants had completed the study. The primary efficacy endpoint was change from baseline in objective daytime cough frequency (from 24 h acoustic recording, Leicester Cough Monitor). The primary efficacy analysis included all participants who received at least one dose of study drug and had at least one post-baseline efficacy measurement. Safety analysis included all those who took at least one dose of study drug. In the second cohort, participants with CIC were randomly assigned in a study across four centres with similar design and endpoints. The study was registered with ClinicalTrials.gov (NCT02412020) and the EU Clinical Trials Register (EudraCT Number 2014-004025-40) and both cohorts are closed to new participants. Findings Between Feb 13, 2015, and Feb 2, 2016, 24 participants with IPF were randomly assigned to treatment groups. 28 participants with CIC were enrolled during the same period and 27 received study treatment. In patients with IPF, PA101 reduced daytime cough frequency by 31·1% at day 14 compared with placebo; daytime cough frequency decreased from a mean 55 (SD 55) coughs per h at baseline to 39 (29) coughs per h at day 14 following treatment with PA101, versus 51 (37) coughs per h at baseline to 52 (40) cough per h following placebo treatment (ratio of least-squares [LS] means 0·67, 95% CI 0·48–0·94, p=0·0241). By contrast, no treatment benefit for PA101 was observed in the CIC cohort; mean reduction of daytime cough frequency at day 14 for PA101 adjusted for placebo was 6·2% (ratio of LS means 1·27, 0·78–2·06, p=0·31). PA101 was well tolerated in both cohorts. The incidence of adverse events was similar between PA101 and placebo treatments, most adverse events were mild in severity, and no severe adverse events or serious adverse events were reported. Interpretation This study suggests that the mechanism of cough in IPF might be disease specific. Inhaled PA101 could be a treatment option for chronic cough in patients with IPF and warrants further investigation

    Measurements of differential production cross sections for a Z boson in association with jets in pp collisions at root s=8 TeV

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