1,720,996 research outputs found
Eomes+ NK-Zellen als bedeutende Lymphozytenpopulation des angeborenen Immunsystems im Dünndarm von Neugeborenen
No full textNatürliche Killerzellen (NK-Zellen) als Teil der Familie der Innate lymphoid cells (ILC) spielen eine entscheidende Rolle in der Verteidigung gegenüber viralen Infektionen aber auch bei der Entwicklung und Wachstum verschiedener Gewebe. Vor diesem Hintergrund waren die Zusammensetzung und Dynamiken intestinaler NK-Zellpopulationen bei Neugeborenen bislang unklar. Diese Periode der Entwicklung ist von besonderem Interesse, da in diesem Intervall ein rasches Wachstum, bakterielle Kolonisation, sowie die erstmalige Exposition gegenüber exogenen Antigenen erfolgt. In dieser Studie zeigen wir, dass CD103+ NK-Zellen die größte ILC-Population im Dünndarm von Neugeborenen bilden. Insbesondere im Kontrast zu adulten Probanden zeigen intestinale NK-Zellen von Neugeborenen einen deutlichen Effektor-Phänotyp welcher sich durch eine hohe Eomes-, Perforin und Granzyme B-Expression auszeichnet und eine stärkere Degranulationskapazität als bei Erwachsenen aufweist. Die absoluten Zahlen jener intestinalen NK-Zellen zeigen sich in den verschiedenen Altersgruppen im ersten Lebensjahr schrittweise rückläufig. Jener Rückgang an NK-Zellen wird begleitet von einem Zuwachs an intestinalen Eomes+ T-Zellen. Im Rahmen dessen verbleibt eine umschriebene Population an epithelialen NKp44+CD69+ NK-Zellen mit geringerer zytotoxischer Potenz bis hin ins Erwachsenenalter. Zusammenfassend lässt sich festhalten, dass in der Dünndarmmukosa von Neugeborenen reichlich NK-Zellen vorzufinden sind, welche dort bereits früh in der Entwicklung immunologische Effektorfunktionen ausüben können, während T-Zellantworten des adaptiven Immunsystems noch heranreifen (Sagebiel et al., 2019)
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
No full textWe 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
Maternal HIV infection alters the immune balance in the mother and fetus; implications for pregnancy outcome and infant health
No full textWith the rapid roll-out of combination antiretroviral therapy to prevent mother-to-child transmission of HIV, there is an annual increase in the number of uninfected infants born to HIV-infected women. Although the introduction of combination antiretroviral therapy has vastly improved pregnancy outcome and the health of infants born to HIV-infected women, concerns remain regarding the impact the maternal HIV infection on the pregnancy outcome and the health of HIV-exposed uninfected infants. Maternal HIV infection is associated with negative pregnancy outcomes such as low birth weight. In addition, an increased susceptibility to infections is reported in HIV-exposed uninfected infants compared with infants born to uninfected women. Studies have shown that HIV-exposure affects the maternal/fetal unit, with increase of proinflammatory cytokine produced by placental cells, as well as altered infant immune responses. These changes could provide the underlying conditions for negative pregnancy outcomes and facilitate mother-to-child transmission of HIV in the infant. Further studies are required to understand the underlying mechanisms and investigate whether these altered infant immune responses persist and have clinical consequences beyond childhood. HIV infection in pregnant women is associated with altered immune responses in HIV-infected women and their offspring with clinical consequences for pregnancy outcome and the HIV-exposed uninfected infant. Further studies are required to address the origin and long-term consequences of prenatal HIV-exposure and subsequent immune activation for infant healt
Can NK cells purge HIV sanctuaries?
No full textA recent study identifies a population of CXCR5(+) natural killer (NK) cells patrolling B cell follicles in simian immunodeficiency virus (SIV)-infected African green monkeys that might contribute to the lack of disease progression in this nonpathogenic mode
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