1,543 research outputs found

    Evaluation of non-chemical seed treatment methods for the control of Alternaria dauci and A. radicina on carrot seeds

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    The current study was initiated to evaluate the efficacy of physical methods (hot water, aerated steam, electron treatment) and agents of natural origin (resistance inducers, plant derived products, micro-organisms) as seed treatments of carrots for control of Alternaria dauci and A. radicina. Control of both Alternaria species by seed treatment with the resistance inducers was generally poor. Results were also not satisfactory with most of the formulated commercial micro-organism preparations. Based on the average of five field trials, one of these, BA 2552 (Pseudomonas chlororaphis), provided a low but significant increase in plant stand. Among the experimental micro-organisms, the best results were obtained with Pseudomonas sp. strain MF 416 and Clonostachys rosea strain IK726. A similar level of efficacy was provided by seed treatment with an emulsion (1%) of thyme oil in water. Good and consistent control was generally achieved with the physical methods aerated steam, hot water and electron treatment. Aerated steam treatment was, apart from the thiram-containing chemical standard, the best single treatment, and its performance may at least partially be due to extensive pre-testing, resulting in dosages optimally adapted to the respective seed lot. In some of the experiments the effect of the hot water treatment, which was tested at a fixed, not specifically adapted dosage, was significantly improved when combined with a Pseudomonas sp. MF 416 or C. rosea IK726 treatment. The results are discussed in relation to the outcome of experiments in which the same seed treatment methods and agents were tested in other seed-borne vegetable pathosystems

    Serum prolactin as a biomarker for the study of intracerebral dopamine effect in adult patients with phenylketonuria: a cross-sectional monocentric study

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    BACKGROUND: It has been previously postulated that high phenylalanine (Phe) might disturb intracerebral dopamine production, which is the main regulator of prolactin secretion in the pituitary gland. Previously, various associations between Phe and hyperprolactinemia were revealed in studies performed in phenylketonuria (PKU) children and adolescents. The aim of the present study was to clarify whether any relation between serum phenylalanine and prolactin levels can be found in adult PKU patients. PATIENTS AND METHODS: We conducted a cross-sectional, monocentric study including 158 adult patients (male n = 68, female n = 90) with PKU. All patients were diagnosed during newborn screening and were treated since birth. Serum Phe, tyrosine (Tyr), prolactin (PRL), and thyroid-stimulating hormone (TSH) levels were measured, and Phe/Tyr ratio was calculated. Males and females were analyzed separately because the serum prolactin level is gender-dependent. RESULTS: No significant correlations were found between serum phenylalanine, tyrosine, or the Phe/Tyr ratio and serum prolactin level either in the male or in the female group. CONCLUSIONS: In treated adult PKU patients, the serum prolactin level may not be significantly influenced by Phe or Tyr serum levels

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Search for direct pair production of the top squark in all-hadronic final states in proton-proton collisions at s√=8 TeV with the ATLAS detector

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    The results of a search for direct pair production of the scalar partner to the top quark using an integrated luminosity of 20.1fb−1 of proton–proton collision data at √s = 8 TeV recorded with the ATLAS detector at the LHC are reported. The top squark is assumed to decay via t˜→tχ˜01 or t˜→ bχ˜±1 →bW(∗)χ˜01 , where χ˜01 (χ˜±1 ) denotes the lightest neutralino (chargino) in supersymmetric models. The search targets a fully-hadronic final state in events with four or more jets and large missing transverse momentum. No significant excess over the Standard Model background prediction is observed, and exclusion limits are reported in terms of the top squark and neutralino masses and as a function of the branching fraction of t˜ → tχ˜01 . For a branching fraction of 100%, top squark masses in the range 270–645 GeV are excluded for χ˜01 masses below 30 GeV. For a branching fraction of 50% to either t˜ → tχ˜01 or t˜ → bχ˜±1 , and assuming the χ˜±1 mass to be twice the χ˜01 mass, top squark masses in the range 250–550 GeV are excluded for χ˜01 masses below 60 GeV

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  μb-1 of data as a function of transverse momentum (pT) and the transverse energy (ΣETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∼0) correlation that grows rapidly with increasing ΣETPb. A long-range “away-side” (Δϕ∼π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ΣETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ΣETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁡2Δϕ modulation for all ΣETPb ranges and particle pT

    Search for new phenomena in final states with an energetic jet and large missing transverse momentum in pp collisions at √ s = 8 TeV with the ATLAS detector

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    Results of a search for new phenomena in final states with an energetic jet and large missing transverse momentum are reported. The search uses 20.3 fb−1 of √ s = 8 TeV data collected in 2012 with the ATLAS detector at the LHC. Events are required to have at least one jet with pT > 120 GeV and no leptons. Nine signal regions are considered with increasing missing transverse momentum requirements between Emiss T > 150 GeV and Emiss T > 700 GeV. Good agreement is observed between the number of events in data and Standard Model expectations. The results are translated into exclusion limits on models with either large extra spatial dimensions, pair production of weakly interacting dark matter candidates, or production of very light gravitinos in a gauge-mediated supersymmetric model. In addition, limits on the production of an invisibly decaying Higgs-like boson leading to similar topologies in the final state are presente

    Diabetes MILES - Australia (Management and Impact for Long-Term Empowerment and Success) : methods and sample characteristics of a national survey of the psychological aspects of living with type 1 or type 2 diabetes in Australian adults

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    Background Successful management of diabetes requires attention to the behavioural, psychological and social aspects of this progressive condition. The Diabetes MILES (Management and Impact for Long-term Empowerment and Success) Study is an international collaborative. Diabetes MILES-Australia, the first Diabetes MILES initiative to be undertaken, was a national survey of adults living with type 1 or type 2 diabetes in Australia. The aim of this study was to gather data that will provide insights into how Australians manage their diabetes, the support they receive and the impact of diabetes on their lives, as well as to use the data to validate new diabetes outcome measures.Methods The survey was designed to include a core set of self-report measures, as well as modules specific to diabetes type or management regimens. Other measures or items were included in only half of the surveys. Cognitive debriefing interviews with 20 participants ensured the survey content was relevant and easily understood. In July 2011, the survey was posted to 15,000 adults (aged 18-70 years) with type 1 or type 2 diabetes selected randomly from the National Diabetes Services Scheme (NDSS) database. An online version of the survey was advertised nationally. A total of 3,338 eligible Australians took part; most (70.4%) completed the postal survey. Respondents of both diabetes types and genders, and of all ages, were adequately represented in both the postal and online survey sub-samples. More people with type 2 diabetes than type 1 diabetes took part in Diabetes MILES-Australia (58.8% versus 41.2%). Most respondents spoke English as their main language, were married/in a de facto relationship, had at least a high school education, were occupied in paid work, had an annual household income &gt; $AUS40,000, and lived in metropolitan areas.Discussion A potential limitation of the study is the under-representation of respondents from culturally and linguistically diverse backgrounds (including Aboriginal and Torres Strait Islander origin). Diabetes MILES-Australia represents a major achievement in the study of diabetes in Australia, where for the first time, the focus is on psychosocial and behavioural aspects of this condition at a national level. <br /

    Inhibition of the inositol kinase Itpkb augments calcium signaling in lymphocytes and reveals a novel strategy to treat autoimmune disease

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    Emerging approaches to treat immune disorders target positive regulatory kinases downstream of antigen receptors with small molecule inhibitors. Here we provide evidence for an alternative approach in which inhibition of the negative regulatory inositol kinase Itpkb in mature T lymphocytes results in enhanced intracellular calcium levels following antigen receptor activation leading to T cell death. Using Itpkb conditional knockout mice and LMW Itpkb inhibitors these studies reveal that Itpkb through its product IP4 inhibits the Orai1/Stim1 calcium channel on lymphocytes. Pharmacological inhibition or genetic deletion of Itpkb results in elevated intracellular Ca2+ and induction of FasL and Bim resulting in T cell apoptosis. Deletion of Itpkb or treatment with Itpkb inhibitors blocks T-cell dependent antibody responses in vivo and prevents T cell driven arthritis in rats. These data identify Itpkb as an essential mediator of T cell activation and suggest Itpkb inhibition as a novel approach to treat autoimmune disease

    Learners in a Changing Learning Landscape: Reflections from an Instructional Design Perspective

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    Van Merriënboer, J. J. G., & Stoyanov, S. (2008). Learners in a changing learning landscape: Reflections from an instructional design perspective. In J. Visser & M. Visser-Valfrey (Eds.), Learners in a changing learning landscape: Reflections from a dialogue on new roles and expectations (pp. 69-90). Dordrecht, The Netherlands: Springer.Both learners and teachers find themselves in a learning landscape that is rapidly changing, along with fast societal and technological developments. This paper discusses the new learning landscape from an instructional design perspective. First, with regard to what is learned, people more than ever need flexible problem-solving and reasoning skills allowing them to deal with new, unfamiliar problem situations in their professional and everyday life. Second, with regard to the context in which learning takes place, learning in technology-rich, informal and professional 24/7 settings is becoming general practice. And third, with regard to the learners themselves, they can more often be characterized as lifelong learners who are mature, bring relevant prior knowledge, and have very heterogeneous expectations and perceptions of learning. High-quality instructional design research should focus on the question which instructional methods and media-method combinations are effective, efficient and appealing in this new learning landscape. Some innovative instructional methods that meet this requirement are discussed
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