1,721,021 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Full text linkWe 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
Die Darmmikrobiota induziert die Eliminierung von C. rodentium durch Phagozyten
No full textInfections with enterohemorrhagic (EHEC) and enteropathogenic (EPEC) Escherichia
coli (E. coli) are a major cause of diarrhoea in the developing world.
Asymptomatic EPEC-carriers are thought to be an important reservoir for these
pathogens since they excrete pathogens unknowingly and thereby infect other
people and spread disease. With C. rodentium we were able to mimic long-termcarrier
situations in mice without gut microbiota. This enabled us to investigate
how commensal bacteria initiate clearance of enteropathogens.
During this work, we could show that a healthy gut microbiota influences the expression
of inflammatory factors like IL-17A and consequently CXCL2 and ICAM-
1, thus mediating migration of neutrophils into the colon. Furthermore, we found
that commensal bacteria enhance the phagocytic activity of neutrophils and in
parallel elevate colonic IgG levels, subsequently leading to an efficient uptake
and killing of C. rodentium. However, our findings demonstrate that in absence of
gut microbiota these immune responses are impaired. As a consequence, this
leads to a lifelong persistence of C. rodentium, which adapt a commensal-like
phenotype at late time points of infection. Importantly, we here show that impaired
immune responses can be restored by the transfer of gut microbiota, thus enabling
clearance of the enteropathogen.
Although many prior investigations have focused on infection with C. rodentium,
it was not understood how gut microbiota induces clearance of the enteropathogen.
The findings from this work might provide information for microbiota mediated
preventive and therapeutic treatments of asymptomatic EPEC-carriers.Infektiöse Durchfallerkrankungen, wie die durch enterohämorrhagische (EHEC)
und enteropathogene (EPEC) E. coli verursachten, stellen besonders in Entwicklungsländern
ein großes medizinisches Problem dar. Symptomlose Langzeitträger
werden als gefährliches Reservoir angesehen, weil sie die Infektion unwissentlich
verbreiten. Mit C. rodentium, einem Modelkeim für EHEC/EPEC Infektionen
in der Maus, konnten wir in keimfreien Mäusen eine Langzeitinfektion etablieren,
um den Einfluss kommensaler Bakterien für die Abwehr von enteropathogenen
Keimen zu erforschen.
Es konnte gezeigt werden, dass die normale, intestinale Mikrobiota die Expression
inflammatorischer Faktoren wie IL-17A, CXCL2 und ICAM-1 beeinflusst, die
an der Migration von Neutrophilen in das Colon beteiligt sind. Zusätzlich konnten
wir zeigen, dass kommensale Keime die phagozytische Aktivität von Neutrophilen
und die Konzentration an IgG im Colon erhöhen und somit eine effiziente
Aufnahme und Abtötung von C. rodentium ermöglichen. Wir konnten weiterhin
zeigen, dass diese Immunreaktionen in Abwesenheit von Darmbakterien stark
beeinträchtigt sind, sodass C. rodentium lebenslang in keimfreien Mäusen persistiert
und sich vom pathogenen in ein kommensales Bakterium verwandelt.
Von enormer Bedeutung ist der Befund, dass die antibakterielle Abwehr durch
den Transfer von Darmbakterien wiederhergestellt werden kann und es zu einer
Eliminierung der enteropathogenen Keime kommt.
Obwohl Infektionen mit C. rodentium im Fokus vieler früherer Forschungsarbeiten
standen, war bisher noch unverstanden, wie Darmbakterien eine Eliminierung
der enteropathogenen Bakterien induzieren. Die aus dieser Arbeit gewonnen Erkenntnisse
können für die präventive und therapeutische Behandlung asymptomatischer
EPEC- Langzeitträger von Bedeutung sein
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
Nahrungszellulose schützt vor intestinalen Entzündungen durch die Förderung der Mikrobiotareifung und Darmbarrierefunktion
No full textDie gesundheitsförderliche Bedeutung von Ballaststoffen in der Nahrung wurden bereits vor fünfzig Jahren entdeckt. Dennoch sind die Mechanismen ihrer Wirkungen auf zellulärer und molekularer Ebene bis heute noch nicht vollständig verstanden, insbesondere im Hinblick auf Nahrungszellulose, dem am weitesten verbreiteten Biopolymer der Erde.
In dieser Studie wurde der Einfluss von Zellulose auf die intestinale Mikrobiota, Immun- sowie Epithelzellen unter homöostatischen und inflammatorischen Bedingungen untersucht. Wir konnten zeigen, dass Zellulose als potenzielles Substrat für Darmbakterien dient und die physiologische Entwicklung der intestinalen Mikrobiota fördert. Der Mangel an Zellulose induzierte eine proinflammatorische Immunantwort, verminderte die Expression des antimikrobiellen REG3g und erhöhte die Anfälligkeit für akute Darmentzündungen.
Eine der am stärksten von Zellulosemangel betroffenen Gattungen der Mikrobiota war Alistipes. Die isolierte Analyse eines dominanten Vertreters dieser Gattung, Alistipes finegoldii, zeigte, dass dieses Bakterium für einige der molekularen und zellulären Effekte von Zellulose verantwortlich war. A. finegoldii, das mit cellulolytischen Enzymen ausgestattet ist, induzierte die Expression von IL-22 und REG3g und stellte die Funktion der Darmbarriere in einem gnotobiotischen Mausmodell wieder her.
Die Ergebnisse dieser Studie unterstützen somit epidemiologische Daten und liefern mögliche Kausalitäten für die gesundheitsförderlichen Wirkungen des Ballaststoffs Zellulose. Da der Verzehr von Ballaststoffen in vielen westlichen Gesellschaften alarmierend gering ist, liefert diese Studie auch die wissenschaftliche Grundlage für mögliche Empfehlungen zur Ballaststoffaufnahme mit dem Ziel, die Ernährungssituation in der Gesellschaft zu verbessern.It is almost fifty years ago that dietary fibres were recognized to be healthpromoting. However, the cellular and molecular mechanisms of health-promoting effects are not yet well understood, especially with respect to dietary cellulose, the most common biopolymer on earth.
In this study, the impact of dietary cellulose on the intestinal microbiota, immune and epithelial cell functions in health and disease was examined. Cellulose served as a potential substrate for intestinal microbes and promoted the maturation of the gut microbiota. Moreover, the lack of this fibre skewed immune responses towards inflammation, decreased the transcription of antimicrobial REG3g and increased the susceptibility to acute colitis.
One of the genera most affected by cellulose deprivation was Alistipes. Analysis of Alistipes finegoldii, a dominant representative of this genus, revealed that this microbe mimics some of the molecular and cellular effects of dietary cellulose in a gnotobiotic mouse model. We found that A. finegoldii is equipped with cellulolytic enzymes and that intestinal colonization led to enhanced expression of IL-22 and REG3g. Functionally, A. finegoldii was able to restore intestinal barrier function during acute colitis.
Collectively, this study supports epidemiological observations and gives a rationale for the health promoting effects of dietary cellulose. Since the intake of fibres in most western societies is very low, this study provides a scientific rationale to set up recommendations on fibre consumption, with special emphasis on cellulose, in order to improve public health
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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