1,218 research outputs found

    A Lightweight Multilevel Markup Language for Connecting Software Requirements and Simulations

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    [Context] Simulation is a powerful tool to validate specified requirements especially for complex systems that constantly monitor and react to characteristics of their environment. The simulators for such systems are complex themselves as they simulate multiple actors with multiple interacting functions in a number of different scenarios. To validate requirements in such simulations, the requirements must be related to the simulation runs. [Problem] In practice, engineers are reluctant to state their requirements in terms of structured languages or models that would allow for a straightforward relation of requirements to simulation runs. Instead, the requirements are expressed as unstructured natural language text that is hard to assess in a set of complex simulation runs. Therefore, the feedback loop between requirements and simulation is very long or non-existent at all. [Principal idea] We aim to close the gap between requirements specifications and simulation by proposing a lightweight markup language for requirements. Our markup language provides a set of annotations on different levels that can be applied to natural language requirements. The annotations are mapped to simulation events. As a result, meaningful information from a set of simulation runs is shown directly in the requirements specification. [Contribution] Instead of forcing the engineer to write requirements in a specific way just for the purpose of relating them to a simulator, the markup language allows annotating the already specified requirements up to a level that is interesting for the engineer. We evaluate our approach by analyzing 8 original requirements of an automotive system in a set of 100 simulation runs

    Effects of oral adenosine 5'-triphosphate and adenosine in enteric-coated capsules on indomethacin-induced permeability changes in the human small intestine: a randomized cross-over study

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    <p>Abstract</p> <p>Background</p> <p>It is well-known that nonsteroidal anti-inflammatory drugs (NSAIDs) can cause damage to the small bowel associated with disruption of mucosal barrier function. In healthy human volunteers, we showed previously that topical administration of adenosine 5'-triphosphate (ATP) by naso-intestinal tube attenuated a rise in small intestinal permeability induced by short-term challenge with the NSAID indomethacin. This finding suggested that ATP may be involved in the preservation of intestinal barrier function. Our current objective was to corroborate the favourable effect of ATP on indomethacin-induced permeability changes in healthy human volunteers when ATP is administered via enteric-coated capsules, which is a more practically feasible mode of administration. Since ATP effects may have been partly mediated through its breakdown to adenosine, effects of encapsulated adenosine were tested also.</p> <p>Methods</p> <p>By ingesting a test drink containing 5 g lactulose and 0.5 g L-rhamnose followed by five-hour collection of total urine, small intestinal permeability was assessed in 33 healthy human volunteers by measuring the urinary lactulose/rhamnose excretion ratio. Urinary excretion of lactulose and L-rhamnose was determined by fluorescent detection high-pressure liquid chromatography (HPLC). Basal permeability of the small intestine was assessed as a control condition (no indomethacin, no ATP/adenosine). As a model of increased small intestinal permeability, two dosages of indomethacin were ingested at 10 h (75 mg) and 1 h (50 mg) before ingesting the lactulose/rhamnose test drink. At 1.5 h before indomethacin ingestion, two dosages of placebo, ATP (2 g per dosage) or adenosine (1 g per dosage) were administered via enteric-coated hydroxypropyl methylcellulose (HPMC) capsules with Eudragit<sup>© </sup>L30D-55.</p> <p>Results</p> <p>Median urinary lactulose/rhamnose excretion ratio (g/g) in the control condition was 0.032 (interquartile range: 0.022–0.044). Compared to the control condition, lactulose/rhamnose ratio after ingestion of indomethacin plus placebo was significantly increased to 0.039 (0.035–0.068); P < 0.01). The indomethacin-induced increase was neither affected by administration of encapsulated ATP (0.047 (0.033–0.065)) nor adenosine (0.050 (0.030–0.067)). Differences in L/R ratios between the conditions with indomethacin plus placebo, ATP or adenosine were not significant.</p> <p>Conclusion</p> <p>In this study, either ATP or adenosine administered via enteric-coated capsules had no effect on indomethacin-induced small intestinal permeability changes in healthy human volunteers. The observed lack of effect of encapsulated ATP/adenosine may have been caused by opening of the enteric-coated supplement at a site distal from the indomethacin-inflicted site. Further studies on site-specific effectiveness of ATP/adenosine on intestinal permeability changes are warranted.</p

    Utility of oropharyngeal real-time PCR for S. pneumoniae and H. influenzae for diagnosis of pneumonia in adults.

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    Efst á síðunni er hægt að nálgast greinina í heild sinni með því að smella á hlekkinn To access publisher's full text version of this article click on the hyperlink at the bottom of the pageor click on the hyperlink at the To access publisher's full text version of this article, please click on the hyperlink in Additional Links field top of the page marked FilesA lack of sensitive tests and difficulties obtaining representative samples contribute to the challenge in identifying etiology in pneumonia. Upper respiratory tract swabs can be easily collected and analyzed with real-time PCR (rtPCR). Common pathogens such as S. pneumoniae and H. influenzae can both colonize and infect the respiratory tract, complicating the interpretation of positive results. Oropharyngeal swabs were collected (n = 239) prospectively from adults admitted to hospital with pneumonia. Analysis with rtPCR targeting S. pneumoniae and H. influenzae was performed and results compared with sputum cultures, blood cultures, and urine antigen testing for S. pneumoniae. Different Ct cutoff values were applied to positive tests to discern colonization from infection. Comparing rtPCR with conventional testing for S. pneumoniae in patients with all tests available (n = 57) resulted in: sensitivity 87 %, specificity 79 %, PPV 59 % and NPV 94 %, and for H. influenzae (n = 67): sensitivity 75 %, specificity 80 %, PPV 45 % and NPV 94 %. When patients with prior antimicrobial exposure were excluded sensitivity improved: 92 % for S. pneumoniae and 80 % for H. influenzae. Receiver operating characteristic curve analysis demonstrated for S. pneumoniae: AUC = 0.65 (95 % CI 0.51-0.80) and for H. influenzae: AUC = 0.86 (95 % CI 0.72-1.00). Analysis of oropharyngeal swabs using rtPCR proved both reasonably sensitive and specific for diagnosing pneumonia caused by S. pneumoniae and H. influenzae. This method may be a useful diagnostic adjunct to other methods and of special value in patients unable to provide representative lower airway samples.Icelandic Center for Research Rannis Landspitali University Hospital Science Fund University of Iceland Research Fun

    Transepithelial Transport and Enzymatic Detoxification of Gluten in Gluten-Sensitive Rhesus Macaques

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    In a previous report, we characterized a condition of gluten sensitivity in juvenile rhesus macaques that is similar in many respects to the human condition of gluten sensitivity, celiac disease. This animal model of gluten sensitivity may therefore be useful toward studying both the pathogenesis and the treatment of celiac disease. Here, we perform two pilot experiments to demonstrate the potential utility of this model for studying intestinal permeability toward an immunotoxic gluten peptide and pharmacological detoxification of gluten in vivo by an oral enzyme drug candidate.Intestinal permeability was investigated in age-matched gluten-sensitive and control macaques by using mass spectrometry to detect and quantify an orally dosed, isotope labeled 33-mer gluten peptide delivered across the intestinal epithelium to the plasma. The protective effect of a therapeutically promising oral protease, EP-B2, was evaluated in a gluten-sensitive macaque by administering a daily gluten challenge with or without EP-B2 supplementation. ELISA-based antibody assays and blinded clinical evaluations of this macaque and of an age-matched control were conducted to assess responses to gluten.Labeled 33-mer peptide was detected in the plasma of a gluten-sensitive macaque, both in remission and during active disease, but not in the plasma of healthy controls. Administration of EP-B2, but not vehicle, prevented clinical relapse in response to a dietary gluten challenge. Unexpectedly, a marked increase in anti-gliadin (IgG and IgA) and anti-transglutaminase (IgG) antibodies was observed during the EP-B2 treatment phase.Gluten-sensitive rhesus macaques may be an attractive resource for investigating important aspects of celiac disease, including enhanced intestinal permeability and pharmacology of oral enzyme drug candidates. Orally dosed EP-B2 exerts a protective effect against ingested gluten. Limited data suggest that enhanced permeability of short gluten peptides generated by gastrically active glutenases may trigger an elevated antibody response, but that these antibodies are not necessarily causative of clinical illness

    Human Small Heat Shock Protein B8 Inhibits Protein Aggregation without Affecting the Native Folding Process

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    : Small Heat Shock Proteins (sHSPs) are key components of our Protein Quality Control system and are thought to act as reservoirs that neutralize irreversible protein aggregation. Yet, sHSPs can also act as sequestrases, promoting protein sequestration into aggregates, thus challenging our understanding of their exact mechanisms of action. Here, we employ optical tweezers to explore the mechanisms of action of the human small heat shock protein HSPB8 and its pathogenic mutant K141E, which is associated with neuromuscular disease. Through single-molecule manipulation experiments, we studied how HSPB8 and its K141E mutant affect the refolding and aggregation processes of the maltose binding protein. Our data show that HSPB8 selectively suppresses protein aggregation without affecting the native folding process. This anti-aggregation mechanism is distinct from previous models that rely on the stabilization of unfolded polypeptide chains or partially folded structures, as has been reported for other chaperones. Rather, it appears that HSPB8 selectively recognizes and binds to aggregated species formed at the early stages of aggregation, preventing them from growing into larger aggregated structures. Consistently, the K141E mutation specifically targets the affinity for aggregated structures without impacting native folding, and hence impairs its anti-aggregation activity

    COMPARZ Post Hoc Analysis: Characterizing Pazopanib Responders With Advanced Renal Cell Carcinoma

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    Background: The phase III COMPARZ study showed noninferior efficacy of pazopanib versus sunitinib in advanced renal cell carcinoma. In this COMPARZ post hoc analysis we characterized pazopanib responders, patient subgroups with better outcomes, and the effect of dose modification on efficacy and safety. Patients and Methods: Patients were randomized to pazopanib 800 mg/d (n = 557) or sunitinib 50 mg/d, 4 weeks on/2 weeks off (n = 553). Secondary end points included time to complete response (CR)/partial response (PR); the proportion of patients with CR/PR ≥10 months and progression-free survival (PFS) ≥10 months; efficacy in patients with baseline metastasis; and logistic regression analyses of patient characteristics associated with CR/PR ≥10 months. Median PFS, objective response rate (ORR), and safety were evaluated in patients with or without dose reductions or interruptions lasting ≥7 days. Results: Median time to response was numerically shorter for patients treated with pazopanib versus sunitinib (11.9 vs. 17.4 weeks). Similar percentages of pazopanib and sunitinib patients had CR/PR ≥10 months (14% and 13%, respectively), and PFS ≥10 months (31% and 34%, respectively). For patients without versus with adverse event (AE)-related dose reductions, median PFS, median overall survival, and ORR were 7.3 versus 12.5 months, 21.7 versus 36.8 months, and 22% versus 42% (all P &lt;.0001) for pazopanib, and 5.5 versus 13.8 months, 18.1 versus 38.0 months, and 16% versus 34% (all P &lt;.0001) for sunitinib; results were similar for dose interruptions. Conclusion: Dose modifications when required because of AEs were associated with improved efficacy, suggesting that AEs might be used as a surrogate marker of adequate dosing for individual patients

    The Associations Between Children's and Adolescents’ Suicidal and Self-Harming Behaviors, and Related Behaviors Within Their Social Networks: A Systematic Review

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    © 2017, Copyright © International Academy for Suicide Research.Social influences—including the suicidal and self-harming behaviors of others—have been highlighted as a risk factor for suicidal and self-harming behavior in young people, but synthesis of the evidence is lacking. A systematic review of 86 relevant papers was conducted. Considerable published evidence was obtained for positive associations between young people's suicidal and self-harming behavior and that of people they know, with those reporting knowing people who had engaged in suicidal or self-harming behaviors more likely to report engaging in similar behaviors themselves. Findings are discussed in relation to a number of methodological and measurement issues—including the role of normative perceptions—and implications for the prevention of suicidal and self-harming behavior are considered
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