1,720,956 research outputs found

    Effect of Face Mask Design and Bias Flow on Rebreathing During Noninvasive Ventilation

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    BACKGROUND: Noninvasive ventilation (NIV) is used to treat respiratory failure because it reduces the risks of endotracheal intubation and postextubation respiratory failure. A wide range of different interfaces is available, but concerns exist about rebreathing. This study evaluated a total face mask with a 2-limb ventilation circuit and separate access for inflow and outflow gas, which was developed to reduce rebreathing. METHODS: In a bench test, a standard total face mask (with a single connector to the ventilation circuit) and the modified total face mask were applied to a mannequin connected to an active breathing simulator. A known CO2 flow (VCO2) was delivered to the mannequin’s trachea. We tested the following settings: CPAP with the mechanical PEEP valve set at 8 cm H2O (with 60 and 90 L/min continuous flow) and pressure support of 6 and 12 cm H2O (with 2 and 15 L/min bias flow). The settings were tested at simulated breathing frequencies of 15 and 30 breaths/min and with VCO2 of 200 and 300 mL/min. The active simulator generated a tidal volume of 500 mL. Airway pressure, air flow, CO2 concentration, and CO2 flow as the product of air flow and CO2 were recorded. RESULTS: The mean volume of CO2 rebreathed and the minimum CO2 inspiratory concentration were significantly lower with the modified mask than with the standard mask. The 15 L/min bias flow significantly decreased rebreathing with the DiMax0 mask, whereas it had no effect with the traditional mask. CONCLUSIONS: A face mask with a two-limb ventilation circuit and separate access for inflow and outflow gas reduces rebreathing during NIV. The addition of bias flow enhances this effect. Further studies are required to verify the clinical relevance

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed

    Variations on the Author

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    “Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship

    Appropriate Similarity Measures for Author Cocitation Analysis

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    We provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis

    L'ortocheratologia e la sua influenza sulla visione binoculare

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    Questo elaborato di tesi propone una revisione della letteratura scientifica, per chiarire e comprendere meglio l'influenza del trattamento ortocheratologico sulla visione binoculare di bambini e giovani adulti miopi. Nella prima parte sono state analizzate le modifiche alle componenti che formano l'area di visione binoculare nitida e singola quali accomodazione, vergenze e loro interazione. Nella seconda parte, è stato analizzato il cambiamento indotto all'anisomiopia. La prima fase del metodo di ricerca adottato, riguarda la raccolta delle pubblicazioni scientifiche disponibili sul portale di ricerca Pubmed. Con questa indagine sono stati raccolti e analizzati 26 studi totali, di cui 16 relativi alla prima parte del lavoro, mentre 10 riguardanti la seconda. I risultati degli studi della prima parte dell'elaborato non sono tutti concordi, ma la maggioranza è favorevole nell'affermare la presenza di miglioramenti binoculari dopo l'ortocheratologia. I risultati delle pubblicazioni riguardanti la seconda parte della tesi sono invece tutti concordi nell'affermare miglioramenti all'anisomiopia. In conclusione, si potrebbero utilizzare tre brevi frasi per riassumere le modifiche che l'ortocheratologia provoca, con variabilità  soggettiva, alla visione binoculare quali: "miglior risposta accomodativa","postura più divergenteâ" e "riduzione delll'anisomiopia

    Dispelling the Myths Behind First-author Citation Counts

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    We conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more sophisticated methods

    Author Index

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    koamabayili/VECTRON-author-checklist: VECTRON author checklist

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    We have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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