656 research outputs found

    Two-dimensional impurity imaging in deep Antarctic ice cores: snapshots of three climatic periods and implications for high-resolution signal interpretation

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    Due to its micrometer-scale resolution and inherently micro-destructive nature, laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) is particularly suited to exploring the thin and closely spaced layers in the oldest sections of polar ice cores. Recent adaptions to the LA-ICP-MS instrumentation mean we have faster washout times allowing state-of-the-art 2-D imaging of an ice core. This new method has great potential especially when applied to the localization of impurities on the ice sample, something that is crucial, to avoiding misinterpretation of the ultra-fine-resolution signals. Here we present the first results of the application of LA-ICP-MS elemental imaging to the analysis of selected glacial and interglacial samples from the Talos Dome and EPICA Dome C ice cores from central Antarctica. The localization of impurities from both marine and terrestrial sources is discussed, with special emphasis on observing a connection with the network of grain boundaries and differences between different climatic periods. Scale-dependent i mage analysis shows that the spatial significance of a single line profile along the main core axis increases systematically as the imprint of the grain boundaries weakens. It is demon-strated how instrumental settings can be adapted to suit the purpose of the analysis, i.e., by either employing LA-ICP-MS to study the interplay between impurities and the ice microstructure or to investigate the extremely thin climate proxy signals in deep polar ice

    Automatic detection of modality with ITGETARUNS

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    In this paper we present a system for modality detection which is then used for Subjectivity and Factuality evaluation. The system has been tested lately on a task for Subjectivity and Irony detection in Italian tweets (http:// www.di.unito.it/~tutreeb/sentipolc-evalita14/index.html), where the performance was 10th and 4th, respectively, over 27 participants overall. We will focus our paper on an internal evaluation where we considered three national newspapers Il Corriere, Repubblica, Libero. This task was prompted by a project on the evaluation of press stylistic features in political discourse. The project used newspaper articles from the same sources over a period of three months, thus including latest political 2013 governmental crisis. We intended to produce a similar experiment and evaluate results in comparison with previous 2011 crisis. In this evaluation, we focused on Subjectivity, Polarity and Factuality which include Modality evaluation. Final graphs at the end of the paper will show results confirming our previous findings about differences in style, with Il Corriere emerging as the most atypicalIn this paper we present a system for modality detection which is then used for Subjectivity and Factuality evaluation. The system has been tested lately on a task for Subjectivity and Irony detection in Italian tweets (http:// www.di.unito.it/~tutreeb/sentipolc-evalita14/index.html), where the performance was 10th and 4th, respectively, over 27 participants overall. We will focus our paper on an internal evaluation where we considered three national newspapers Il Corriere, Repubblica, Libero. This task was prompted by a project on the evaluation of press stylistic features in political discourse. The project used newspaper articles from the same sources over a period of three months, thus including latest political 2013 governmental crisis. We intended to produce a similar experiment and evaluate results in comparison with previous 2011 crisis. In this evaluation, we focused on Subjectivity, Polarity and Factuality which include Modality evaluation. Final graphs at the end of the paper will show results confirming our previous findings about differences in style, with Il Corriere emerging as the most atypica

    CHARM facility remotely controlled platform at CERN: A new fault-tolerant redundant architecture

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    Many power electronics applications require high tolerance to faults such as short circuit or open circuit of the control signals. One such application is the CERN High energy AcceleRator Mixed-field (CHARM) facility, where maintenance may be precluded for long periods of time due to radiation and, therefore, high reliability is necessary. A redundant interconnection architecture for the control signals is proposed, where each signal is individually processed by different CPUs and transmitted through separate interconnection lines. During normal operation, the CPUs are synchronized and produce the same signals. The purpose of the proposed hardware and firmware strategy is to allow the actuator to continue operating even in case of fault; regardless of the fault type (open circuit, short circuit to ground or to positive supply), a fault on one of the parallel lines would not inhibit the correct operation of the remaining line. This solution can be used to control the movements of a target system using a remote joystick in a safe environment. The architecture features reliable transmission of PWM signals driving a half-bridge power converter. Moreover, it is possible to extend it to any type of converter such as three-phase bridges, three-level NPC, or buck-boost converters. Simulations and experimental results show a good agreement, proving the effectiveness of the proposed fault tolerant circuitry

    A computational approach to implicit entities and events in text and discourse

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    In this paper we will focus on the notion of “implicit” or lexically unexpressed linguistic elements that are nonetheless necessary for a complete semantic interpretation of a text. We refer to “entities” and “events” because the recovery of the implicit material may affect all the modules of a system for semantic processing, from the grammatically guided components to the inferential and reasoning ones. Reference to the system GETARUNS offers one possible implementation of the algorithms and procedures needed to cope with the problem and enables us to deal with all the spectrum of phenomena. The paper will address at first the following three types of “implicit” entities and events: – the grammatical ones, as suggested by a linguistic theories like LFG or similar generative theories; – the semantic ones suggested in the FrameNet project, i.e. CNI, DNI, INI; – the pragmatic ones: here we will present a theory and an implementation for the recovery of implicit entities and events of (non-) standard implicatures. In particular we will show how the use of commonsense knowledge may fruitfully contribute to find relevant implied meanings. Last Implicit Entity only touched on, though for lack of space, is the Subject of Point of View, which is computed by Semantic Informational Structure and contributes the intended entity from whose point of view a given subjective statement is expressed

    Trends and risk factors for syphilis infection in Piedmont Region, Italy, 2002-2008

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    Background: This work aims to analyze trends of syphilis infections in the Piedmont Region (Italy) between 2002 and 2008, and to evaluate risk factors for infection. Methods: Syphilis trends were described according to socio-demographic characteristics, sexual behavior, condom use, number of partners and HIV infection. Independent risk factors for syphilis among men having sex with men (MSM), men having sex with women (MSW), and women were identified through logistic regression comparing cases with 12,773 negative patients. Results: Between 2002 and 2008, 1,046 cases of syphilis were diagnosed, with peaks in 2004 and 2007. The risk of a syphilis diagnosis was independently associated with being older than 24, having a low education level, homosexual behavior, HIV self-reported infection (for MSM and MSW), number of partners (for MSW and women) and non- consistent condom use (for women). Conclusions: Recent outbreaks suggest that the attention to syphilis can’t be lowered. Screening, treatment of cases and notification of partners should be reinforced and integrated with sexual health education and counselling in high-risk environments. Surveillance data must be continuously collected

    Receptor-Coupled Phosphoinositide Hydrolysis in Human Retinal Pigment Epithelium

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    Carbachol and histamine stimulated phosphoinositide (PPI) hydrolysis in cultured human retinal pigment epithelium (RPE), as reflected by an accumulation of 3 H-inositol phosphates in the presence of 10 m M Li + . Carbachol increased PPI hydrolysis to greater than 600% of basal with an EC 50 of 60 Μ M ; stimulation was linear up to 60 min. This activation likely occurred via the M 3 muscarinic cholinergic receptor based on the IC 50 values for 4-diphenylacetoxy- N -methylpiperidine methiodide (0.47 n M ), pirenzepine (280 n M ), and 11-[[2-[(diethylamino)methyl]-1-piperidinyl]-acetyl]-5,11-dihydro-6 H -pyrido[2,3- b ][1,4]benzodiazepin-6-one (1.4 Μ M ). Carbachol-mediated PPI hydrolysis was decreased by 80% in the absence of extracellular Ca 2+ . Histamine stimulated PPI turnover in a linear manner by 180% with an EC 50 of 20 Μ M by the H 1 histaminergic receptor. Serotonin, glutamate, norepinephrine, and dopamine were inactive. In human RPE, the resting cytoplasmic Ca 2+ concentration, as determined by fura-2 fluorescence, was 138 ± 24 n M . On the addition of carbachol, there was a 180% increase in peak intracellular Ca 2+ ; addition of histamine increased intracellular Ca 2+ by 187%. These results suggest receptor-mediated, inositol lipid hydrolysis is coupled to intracellular Ca 2+ flux in human RPE.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66430/1/j.1471-4159.1991.tb03471.x.pd

    Holocene regional gradients of dust provenance and flux between Talos Dome and Dome C, East Antarctica.

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    Aeolian sequences from Central East Antarctic ice cores provide climate and environmental information of hemispheric significance. Close to the margins of the ice sheet, high-elevation ice-free terrains protruding above the ice sheet surface can provide an additional input of fine dust particles to the atmosphere, making peripheral locations particularly interesting for the study of the regional climate evolution. In the Talos Dome area of East Antarctica, entrainment and transport of local mineral particles is merely influenced by local wind direction and strength, which in turn is tuned by regional climate changes. We investigate the spatial variability of modern and Holocene dust flux, grain size and isotopic (Sr-Nd) composition along a hypothetic transect from Talos Dome all through the interior of the ice sheet (Dome C/Vostok area), and compare the geochemical fingerprint of dust extracted from firn and ice cores to the equivalent size fraction of regolith and glacial deposits from high altitude Victoria Land sources. This study aims to better understand the environmental gradients of dust flux and provenance from the marginal Talos Dome site to the higher Dome C drainage area, with implications for the regional atmospheric circulation, while documenting the isotopic composition of local exposed sediments

    Synthesis and crystal structure of C2/c Ca(Co, Mg)Si2O6 pyroxenes : effect of the cationic substitution on the cell volume

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    A series of clinopyroxenes along the CaMgSi2O6-CaCoSi2O6 join was synthesized by quenching from melt at 1500\ub0C and subsequent annealing at 1250\ub0C (at 0.0001 GPa). This protocol proved to be the most effective to obtain homogenous, impurity free and stoichiometric pyroxenes as run products. Electron microprobe analyses in energy-dispersive mode were conducted and single-crystal X-ray diffraction data were collected on the Ca(CoxMg1-x)Si2O6 pyroxenes, with x = 0.2, 0.4, 0.5, 0.6; anisotropic structure refinements were performed. The effects of the cation substitution at the M1 site are described at the atomic level. The experimental findings of this study allowed us to extend the comparative analysis of the structural features of pyroxenes with divalent cations at the M1 and M2 sites

    Case Report: Stevens-Johnson Syndrome and Hepatotoxicity Induced by Osimertinib Sequential to Pembrolizumab in a Patient With EGFR-Mutated Lung Adenocarcinoma

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    Background: Lung cancer is a complex disease with many subtypes. However, histochemical characteristics, and genetic mutation determinations are contributing to better define therapeutic targets and new drugs. Although this guarantees patients the possibility of obtaining tailored treatment, it makes it more difficult for clinicians patient management more difficult for clinicians who have to define the most suitable therapeutic strategy and to deal with new treatment-related adverse events (TRAEs). It has been seen that the administration of a tyrosine kinase inhibitor (TKI) sequential to an immune checkpoint inhibitor (ICI) can lead to a higher rate of severe and life-threatening TRAEs. We report the case of a patient with advanced non-small cell lung cancer (NSCLC) who experienced severe hepatotoxicity and Stevens-Johnson syndrome (SJS) induced by osimertinib sequential to pembrolizumab. Case presentation: A 54-year-old woman with advanced NSCLC received one cycle of chemotherapy plus pembrolizumab after diagnosis. Ten days later she began osimertinib 80 mg daily because epidermal growth factor receptor (EGFR) analysis had revealed an exon 19 deletion. On day 23 of osimertinib the patient experienced an episode of grade (G) 3 hepatotoxicity resolved by discontinuing osimertinib and corticosteroid therapy. The patient restarted osimertinib 80 mg daily after the remission of symptoms but was hospitalized 14 days later following a second episode of severe G3 hepatotoxicity and the onset of SJS, successfully treated with high-dose corticosteroids. Despite the short exposure to osimertinib, the patient obtained a good pathological response. Conclusion: It is important to alert clinicians to carefully evaluate the sequential therapeutic strategy in patients with NSCLC who are candidates for TKI- or ICI-based treatment. Our experience suggests that the use of tyrosine kinase inhibitors (TKIs) as front-line treatment is a more reasonable and safe option for EGFR-mutated lung adenocarcinoma, with ICIs considered as a possible further treatment in sequential approaches
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