120 resultados para Scheurl, Christoph, 1481-1542.
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A new iron(II) coordination polymer, [FeCl2(NC7H9)2(N2C12H12)], has been synthesized under solvothermal conditions and structurally characterized by single-crystal X-ray diffraction. This material crystallizes in the monoclinic space group C2/c, with a = 11.2850(6), b = 13.8925(7), c = 17.0988(9) Å and β = 94.300(3)º (Z = 4). The crystal structure consists of neutral zig-zag chains, in which the iron(II) ions are octahedrally coordinated. The infinite polymer chains are packed into a three-dimensional structure through C–H···Cl interactions. Magnetic susceptibility measurements reveal the existence of weak antiferromagnetic interactions between the iron(II) ions. The effective magnetic moment, μ eff = 5.33 μ B , is consistent with a high-spin iron(II) configuration.
Validation of a priori CME arrival predictions made using real-time heliospheric imager observations
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Between December 2010 and March 2013, volunteers for the Solar Stormwatch (SSW) Citizen Science project have identified and analyzed coronal mass ejections (CMEs) in the near real-time Solar Terrestrial Relations Observatory Heliospheric Imager observations, in order to make “Fearless Forecasts” of CME arrival times and speeds at Earth. Of the 60 predictions of Earth-directed CMEs, 20 resulted in an identifiable Interplanetary CME (ICME) at Earth within 1.5–6 days, with an average error in predicted transit time of 22 h, and average transit time of 82.3 h. The average error in predicting arrival speed is 151 km s−1, with an average arrival speed of 425km s−1. In the same time period, there were 44 CMEs for which there are no corresponding SSW predictions, and there were 600 days on which there was neither a CME predicted nor observed. A number of metrics show that the SSW predictions do have useful forecast skill; however, there is still much room for improvement. We investigate potential improvements by using SSW inputs in three models of ICME propagation: two of constant acceleration and one of aerodynamic drag. We find that taking account of interplanetary acceleration can improve the average errors of transit time to 19 h and arrival speed to 77 km s−1.
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OBJECTIVE: We aimed to examine parents' views regarding their preadolescent child's presence during discussions about serious illnesses. METHODS: In-depth qualitative interviews with parents of children receiving treatment for acute lymphoblastic leukemia were conducted. Parents were sampled from 6 UK treatment centers. Analysis was informed by the constant comparative method and content analysis. RESULTS: We report on interviews with 53 parents (33 mothers, 20 fathers). Parents acknowledged the benefits of communicating openly with children, but few thought that their child's presence in discussions was straightforwardly desirable. They described how their child's presence restricted their own communication with physicians, made concentrating difficult, and interfered with their efforts to care for their child emotionally. Children's presence was particularly difficult when significant issues were being discussed, including prognoses, adverse results, and certain medical procedures. Parents felt that such discussions posed a potential threat to their child, particularly when they had not first had an opportunity to discuss information with the physician separately from the child. In contrast, separate meetings enabled parents to absorb information and to convey it to their child at an appropriate time and in a reassuring way. Some parents experienced difficulties in accessing separate meetings with physicians. CONCLUSIONS: The difficulties parents described could potentially be addressed by extending, beyond the diagnosis period, the practice of sequencing significant information so that it is communicated to parents in separate meetings before being communicated to the child and by periodically exploring with parents what information would be in each child's interests.
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Glycoprotein VI and C-type lectin-like receptor 2 are essential platelet activating receptors in hemostasis and thrombo-inflammatory disease, which signal through a (hem)immunoreceptor tyrosine-based activation motif (ITAM)-dependent pathway. The adapter molecules Src-like adapter proteins (SLAP and SLAP2) are involved in the regulation of immune cell surface expression and signaling, but their function in platelets is unknown. In this study, we show that platelets expressed both SLAP isoforms and that overexpression of either protein in a heterologous cell line almost completely inhibited glycoprotein VI and C-type lectin-like receptor 2 signaling. In mice, single deficiency of SLAP or SLAP2 had only moderate effects on platelet function, whereas double deficiency of both adapters resulted in markedly increased signal transduction, integrin activation, granule release, aggregation, procoagulant activity, and thrombin generation in response to (hem)ITAM-coupled, but not G protein-coupled, receptor activation. In vivo, constitutive SLAP/SLAP2 knockout mice displayed accelerated occlusive arterial thrombus formation and a dramatically worsened outcome after focal cerebral ischemia. This was attributed to the absence of both adapter proteins in platelets, as demonstrated by adoptive transfer of Slap(-/-)/Slap2(-/-) platelets into wild-type mice. Our results establish SLAP and SLAP2 as critical inhibitors of platelet (hem)ITAM signaling in the setting of arterial thrombosis and ischemic stroke.
Resumo:
Observations from the Heliospheric Imager (HI) instruments aboard the twin STEREO spacecraft have enabled the compilation of several catalogues of coronal mass ejections (CMEs), each characterizing the propagation of CMEs through the inner heliosphere. Three such catalogues are the Rutherford Appleton Laboratory (RAL)-HI event list, the Solar Stormwatch CME catalogue, and, presented here, the J-tracker catalogue. Each catalogue uses a different method to characterize the location of CME fronts in the HI images: manual identification by an expert, the statistical reduction of the manual identifications of many citizen scientists, and an automated algorithm. We provide a quantitative comparison of the differences between these catalogues and techniques, using 51 CMEs common to each catalogue. The time-elongation profiles of these CME fronts are compared, as are the estimates of the CME kinematics derived from application of three widely used single-spacecraft-fitting techniques. The J-tracker and RAL-HI profiles are most similar, while the Solar Stormwatch profiles display a small systematic offset. Evidence is presented that these differences arise because the RAL-HI and J-tracker profiles follow the sunward edge of CME density enhancements, while Solar Stormwatch profiles track closer to the antisunward (leading) edge. We demonstrate that the method used to produce the time-elongation profile typically introduces more variability into the kinematic estimates than differences between the various single-spacecraft-fitting techniques. This has implications for the repeatability and robustness of these types of analyses, arguably especially so in the context of space weather forecasting, where it could make the results strongly dependent on the methods used by the forecaster.
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Understanding Digital Literacies provides an accessible and timely introduction to new media literacies. It supplies readers with the theoretical and analytical tools with which to explore the linguistic and social impact of a host of new digital literacy practices. Each chapter in the volume covers a different topic, presenting an overview of the major concepts, issues, problems and debates surrounding the topic, while also encouraging students to reflect on and critically evaluate their own language and communication practices. Features include: coverage of a diverse range of digital media texts, tools and practices including blogging, hypertextual organisation, Facebook, Twitter, YouTube, Wikipedia, websites and games an extensive range of examples and case studies to illustrate each topic, such as how blogs have affected our thinking about communication, how the creation and sharing of digital images and video can bring about shifts in social roles, and how the design of multiplayer online games for children can promote different ideologies a variety of discussion questions and mini-ethnographic research projects involving exploration of various patterns of media production and communication between peers, for example in the context of Wikinomics and peer production, social networking and civic participation, and digital literacies at work end of chapter suggestions for further reading and links to key web and video resources a companion website providing supplementary material for each chapter, including summaries of key issues, additional web-based exercises, and links to further resources such as useful websites, articles, videos and blogs.
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Group exhibition curated by Plastique Fantastique. Organised by David Burrows and Dean Kenning in collaboration with Ami Clarke, Andrew Conio, John Cussans and David Osbaldeston. Contributors: David Burrows, Rachel Cattle & Jenna Collins, Neil Chapman & Gillian Wylde, Ami Clarke, Richard Cochrane, Andrew Conio, John Cussans, David Burrows, Benedict Drew, English Heretic, Nikolaus Gansterer, Joey Holder, Dean Kenning, Christoph Lueder, Stine Llungdalh, Adelheid Mers, Mike Nelson, Paul O'Kane, David Osbaldeston, Plastique Fantastique, Patricia Reed, John Russell, Erica Scourti, Andy Sharp, Kamini Vellodi, Martin Westwood and Carey Young.
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This article offers a historical perspective on an important and controversial issue within the emerging field of paediatric palliative care: the question of whether to talk to terminally ill children about their prognosis.
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Small-scale anaerobic digester installation has been a development objective of the Indian government to provide rural households clean fuel. Anaerobic digester installation is heavily subsidised. Depending on caste, the rate of subsidy offered for the smallest system available (1m3) varies between 32.35% and 41.18% of the total installation price. Yet, there are gaps in knowledge regarding the usefulness of such subsidies from a sustainability perspective. A cost-benefit analysis was conducted to evaluate the circumstances required for digester sustainability. The analysis used household data collected from 115 cattle owning households in Odisha, India to evaluate profitability at three levels of subsidy (none, General caste subsidy, and Schedule Caste/Schedule Tribe subsidy). Additional analyses considered the effect of; taking a loan, replacing electric lighting with biogas lighting, and the wealth level of the household. The results indicated that access to subsidy improved profitability. Yet, profitability could be achieved without the use of subsidy. The level of benefit accrued by households was similar independent of wealth. However, the provision of subsidy was essential for ensuring profitability for those households required to take a loan to meet the expense of installation. Such findings highlight the importance of subsidy as a means of including the poor.
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The apoplast is the arena in which endophytic pathogens such as Pseudomonas syringae grow and interact with plant cells. Using metabolomic and ion analysis techniques, this study shows how the composition of Phaseolus vulgaris leaf apoplastic fluid changes during the first six hours of compatible and incompatible interactions with two strains of Pseudomonas syringae pv. phaseolicola (Pph) that differ in the presence of the genomic island PPHGI-1. Leaf inoculation with the avirulent island-carrying strain Pph 1302A elicited effector-triggered immunity (ETI) and resulted in specific changes in apoplast composition, including increases in conductivity, pH, citrate, γ-aminobutyrate (GABA) and K+, that are linked to the onset of plant defence responses. Other apoplastic changes, including increases in Ca2+, Fe2/3+ Mg2+, sucrose, β-cyanoalanine and several amino acids, occurred to a relatively similar extent in interactions with both Pph 1302A and the virulent, island-less strain Pph RJ3. Metabolic footprinting experiments established that Pph preferentially metabolizes malate, glucose and glutamate, but excludes certain other abundant apoplastic metabolites, including citrate and GABA, until preferred metabolites are depleted. These results demonstrate that Pph is well-adapted to the leaf apoplast metabolic environment and that loss of PPHGI-1 enables Pph to avoid changes in apoplast composition linked to plant defences.
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Southward Interplanetary Magnetic Field (IMF) in the Geocentric Solar Magnetospheric (GSM) reference frame is the key element that controls the level of space-weather disturbance in Earth’s magnetosphere, ionosphere and thermosphere. We discuss the relation of this geoeffective IMF component to the IMF in the Geocentric Solar Ecliptic (GSE) frame and, using the almost continuous interplanetary data for 1996-2015 (inclusive), we show that large geomagnetic storms are always associated with strong southward, out-of-ecliptic field in the GSE frame: dipole tilt effects, that cause the difference between the southward field in the GSM and GSE frames, generally make only a minor contribution to these strongest storms. The time-of-day/time-of-year response patterns of geomagnetic indices and the optimum solar wind coupling function are both influenced by the timescale of the index response. We also study the occurrence spectrum of large out-of-ecliptic field and show that for one-hour averages it is, surprisingly, almost identical in ICMEs (Interplanetary Coronal Mass Ejections), around CIRs/SIRs (Corotating and Stream Interaction Regions) and in the “quiet” solar wind (which is shown to be consistent with the effect of weak SIRs). However, differences emerge when the timescale over which the field remains southward is considered: for longer averaging timescales the spectrum is broader inside ICMEs, showing that these events generate longer intervals of strongly southward average IMF and consequently stronger geomagnetic storms. The behavior of out-of-ecliptic field with timescale is shown to be very similar to that of deviations from the predicted Parker spiral orientation, suggesting the two share common origins.