1,720,963 research outputs found
De rol van de vitamine D pathway in de aangeboren immuunrespons in COPD
Chronic obstructive pulmonary disease (COPD) is a chronic lung disease affecting millions of people worldwide. Enhanced inflammatory responses within the airways is one of the key characteristics in the pathophysiology of COPD. Although cigarette smoking is the major risk factor, only around 20% of smokers actually develop COPD. Therefore, other risk factors must be involved in COPD onset and progression. We hypothesize that vitamin D deficiency, which is highly prevalent worldwide and even more so in COPD patients, could be such a risk factor for COPD onset and progression because of its anti-inflammatory and antibacterial potential.
The use of our established mouse model of CS-induced COPD allowed us to elucidate whether vitamin D deficiency is a causal contributing factor to COPD onset and progression. In Chapter 3, we demonstrate that vitamin D deficiency greatly enhances airway and parenchymal inflammation in a mouse model of subacute and chronic CS exposure, resulting in early onset of emphysema and consistent lung hyperinflation. Our data further strengthen the epidemiological associations that link vitamin D deficiency to COPD onset and progression (lung function decline, exacerbations).
Respiratory bacterial infections, such as nontypeable Haemophilus influenzae (NTHi), are the major trigger for COPD exacerbations and amplify the ongoing inflammation in COPD. In Chapter 4, we have investigated whether vitamin D deficiency may affect bacterial clearance and acute inflammatory response to a respiratory infection with NTHi. Although results are preliminary and additional research is necessary, our results suggest that vitamin D deficiency may amplify acute inflammatory responses directly following NTHi infection, leading to a more rapid clearance of the infection and accompanying inflammation.
As vitamin D deficiency is highly prevalent worldwide, our results implicate that vitamin D may be a promising strategy to prevent COPD onset and progression. However, it is currently not known whether the active form of vitamin D, 1,25-dihydroxyvitamin D (1,25(OH)2D), can indeed exert anti-inflammatory and antibacterial functions within CS-compromised airways. By using in vitro cell research, we have demonstrated in Chapter 5 that 1,25(OH)2D dampens levels of important inflammatory mediators (IL-8, TNF-a, MCP-1) released by alveolar macrophages from (non-) smoking subjects and released by cigarette smoke extract (CSE)-treated THP-1 macrophages (cell line model for alveolar macrophages). 1,25(OH)2D furthermore enhanced the release of the important antimicrobial peptide cathelicidin from alveolar macrophages from (non-)smoking subjects and CSE-treated THP-1 macrophages. As we have shown that vitamin D metabolism in THP-1 macrophages is not affected by CS exposure, our results suggest that 1,25(OH)2D can exert its anti-inflammatory and antibacterial functions within the airways of smoking subjects and in this way could potentially decrease susceptibility to COPD in those subjects.
Although our data support the use of vitamin D supplementation as a means for reducing COPD onset and progression, (high-dose) vitamin D supplementation may lead to high serum vitamin D levels, which have been previously associated with increased risk of adverse outcomes. In Chapter 6, we demonstrate that high serum vitamin D levels, resulting from high-dose vitamin D supplementation, enhance characteristic disease features of COPD (emphysema, lung hyperinflation, pulmonary inflammation) in our mouse model of subacute and chronic CS exposure. These results together with the results from Chapter 3 suggest that there may be an optimal range for serum vitamin D levels.
Taken together, our data demonstrate an important role for the vitamin D pathway in COPD onset and progression and support the need for more well-designed intervention studies with vitamin D supplementation.status: Publishe
Going Beyond Counting First Authors in Author Co-citation Analysis
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
“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
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
Dispelling the Myths Behind First-author Citation Counts
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
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
Author-wise bibliometric analysis based on entropy.
Author-wise bibliometric analysis based on entropy.</p
Author Under Sail The Imagination of Jack London, 1893-1902
In Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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