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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
IL-12-Impaired and IL-12-Secreting Dendritic Cells Produce IL-23 upon CD154 Restimulation
No full textDispelling 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
In-vitro-and in-vivo-studies of IL-12-deficient dendritic cells in primates
No full textTitelblatt und Inhaltsverzeichnis
Einleitung
Material und Methoden
Ergebnisse
Diskussion
Ausblick
Zusammenfassung
Literaturverzeichnis
Abkürzungsverzeichnis
PublikationenIL-12 wird aus den Untereinheiten p35 und p40 aufgebaut, wobei p40 auch in
Assoziation mit p19 als IL-23 vorliegen kann. Daten von Patienten, die IL-12-
oder IL-12-Rezeptor-Immundefizienzen aufweisen, widersprechen der
Notwendigkeit von IL-12 für die Induktion von Th1-Immunantworten im Menschen.
Dies führte zu der Vermutung, dass bei Menschen andere Mechanismen existieren,
die eine IL-12-Defizienz kompensieren können. Dendritische Zellen (DCs) sind
in der Lage, die Zytokine der IL-12-Familie zu produzieren und naive CD4+
T-Lymphozyten zu aktivieren. Um die Bedeutung von IL-12 für die Induktion
zellulärer Immunantworten zu untersuchen, wurden in der vorliegenden Arbeit
IL-12-defiziente DCs aus monozytären Blutvorläuferzellen gewonnen und in vitro
sowie in vivo hinsichtlich ihrer immunologischen Eigenschaften analysiert.
Hierfür wurde der Rhesusaffe (Macaca mulatta) aufgrund seiner engen
phylogenetischen und immunologischen Verwandtschaft zum Menschen als
Tiermodell gewählt. Um neben peripheren auch mukosale Immunantworten nach
Reinjektion IL-12-defizienter DCs zu erfassen, wurde zunächst in Vorstudien
untersucht, inwieweit funktional intakte Leukozyten aus mukosalen Gewebeproben
von Rhesusaffen isoliert werden können. Magenbioptate erwiesen sich aufgrund
der niedrigen Zellzahlen und unzureichenden Reinheit der isolierten Zellen als
ungeeignetes Ausgangsmaterial für funktionelle Untersuchungen. Dagegen konnten
aus mukosalen Resektaten isolierte Leukozyten für funktionelle Untersuchungen
antigenspezifischer Immunantworten verwendet werden. Da Studien, die auf dem
Einsatz ex vivo gewonnener, reinjizierter DCs basieren, eine relativ große
Anzahl von DCs erfordern, wurden außerdem im Vorfeld Untersuchungen zur
Mobilisierung von Monozyten in peripheren Blut der Spendertiere mittels
rekombinanter humaner Zytokine durchgeführt. Die Behandlung von Rhesusaffen
mit rhGM-CSF führte zu einer 30-fachen Steigerung der Monozytenzahl. Eine
zweite Applikation von rhGM-CSF blieb jedoch bei vorbehandelten Tieren ohne
Effekt aufgrund der Induktion neutralisierender Antikörper. Die Behandlungen
mit rhG-CSF resultierten dagegen wiederholt in einer 2-3-fachen Erhöhung der
Monozytenzahl. Daher wurden die Tiere vor Gewinnung der Blutproben für die In-
vivo-Experimente mit rhG-CSF behandelt. Das immunomodulatorische synthetischen
Polypeptid Glatirameracetat (GA) in Kombination mit dem c-AMP-Derivat,
dibutyryl-cAMP (d-cAMP) aktivierte monozytenabgeleitete Rhesusaffen-DCs, ohne
eine IL-12-Produktion hervorzurufen. GA/d-cAMP-aktivierte Zellen zeigten
Charakteristika reifer DCs, darunter eine hohe Oberflächenexpression MHC-
Klasse II- und kostimulatorischer Moleküle (CD40, CD80, CD86), von CD83 und
CCR7, sowie eine reduzierte Endozytosekapazität. Die Phosphorylierung der p38
-MAP-Kinase wurde in GA/d-cAMP-stimulierten DCs nicht induziert.
Dementsprechend sezernierten diese Zellen signifikant weniger IL-12p40
(p<0,001) als zytokinaktivierte Zellen. Die Sekretion von CCL3 wurde jedoch
nicht inhibiert, und die Zellen sezernierten kein IL-10. GA/d-cAMP-stimulierte
DCs aktivierten effektiv antigenspezifische Th1-Gedächniszellen in vitro. Nach
In-Vitro-Stimulierung naiver CD4+ T-Lymphozyten mit GA/d-cAMP-aktivierten,
verglichen mit zytokinaktivierten DCs war der Anteil Th1-polarisierter
Lymphozyten geringer. 36 h nach intradermaler, jedoch nicht nach subkutaner
Applikation, wurden GA/d-cAMP-aktivierte fluorochrommarkierte DCs in den
parakortikalen T-Zellarealen der drainierenden Lymphknoten nachgewiesen.
GA/d-cAMP- und zytokinaktivierte proteinantigenbeladene DCs induzierten nach
intradermaler Injektion qualitativ ähnliche Th-Immunantworten, die durch die
Produktion von IL-2, IFN-gamma, TNF-alpha und IL-17 charakterisiert waren.
Daneben führte die Applikation sowohl GA/d-cAMP- als auch zytokinaktivierter
DCs zur Expansion peripherer CD4+Foxp3+ regulatorischer T-Lymphozyten. Die
qualitativ ähnlichen In-Vivo-Immunantworten nach Verabreichung
IL-12-defizienter und IL-12-produzierender DCs könnten damit erklärt werden,
dass nach Reinjektion weitere Faktoren, darunter Bestandteile extrazellulärer
Matrix oder CD40-Ligand (CD40L), die Eigenschaften der DCs beeinflusst haben.
So sezernierten GA/d-cAMP-aktivierte DCs nach In-Vitro-Restimulierung mit
rekombinantem CD40L IL-12p40 und IL-23 in vergleichbaren Konzentrationen wie
CD40L-restimulierte, zytokinaktivierte DCs. Die in dieser Arbeit beschriebene
Induktion ähnlicher Th-Immunantworten durch IL-12-defiziente und
IL-12-produzierende DCs in vivo legt nahe, dass IL-12-defiziente DCs über
andere Mechanismen, unter Umständen durch die Sekretion von IL-23, in der Lage
sind, proinflammatorische Immunantworten zu induzieren.IL-12 consists of a p35 and a p40 subunit, but p40 can also associate with a
p19 subunit to form IL-23. Data from patients with IL-12- or IL-12-receptor
immunodeficiencies argue against the requirement of IL-12 for the induction of
Th1-immune responses in humans. Therefore, mechanisms may exist in humans,
which can partially compensate for an IL-12-deficiency. Dendritic cells (DCs)
are able to produce the cytokines of IL-12-family and to activate naïve CD4+ T
lymphocytes. To study the importance of IL-12 for the induction of cellular
immune responses in primates, IL-12-deficient DCs were generated from
monocytic blood precursors and analysed in vitro as well as in vivo regarding
their immunological properties. Rhesus macaques (Macaca mulatta) were selected
as the animal model because of their close phylogenetical and immunological
relation to humans. To be able to analyse besides systemic also mucosal immune
responses, we first investigated whether functionally intact leukocytes could
be isolated from mucosal tissues. Because of the low cell numbers and
insufficient purity of the isolated cells, stomach biopsies were not suitable
for functional studies. In contrast, leukocytes from jejunal or rectal
sections could be used for studies of antigen-specific immune responses. Since
experiments on the basis of ex-vivo generated, re-injected DCs require
relatively high numbers of DCs, we examined additionally whether monocytes can
be mobilized in the peripheral blood of the donor animals by the application
of recombinant human cytokines. Following the treatment of rhesus macaques
with rhGM-CSF a 30-times increase in monocyte numbers was observed. However, a
second application of rhGM-CSF was ineffective in pre-treated animals due to
the induction of neutralizing antibodies. In contrast, the treatment with rhG-
CSF repeatedly resulted in a 2 to 3-times increase in monocytes numbers.
Therefore, in the in-vivo-experiments the animals were treated with rhG-CSF
prior to the collection of blood samples. The immunomodulatory synthetic
polypeptide glatirameracetate (GA) in combination with the cAMP-derivative,
dibutyryl-cAMP (d-cAMP) activated monocyte-derived rhesus monkey DCs without
the induction of IL-12 secretion. GA/d-cAMP-activated cells showed
characteristics of mature DCs including high surface expression of MHC class
II- and co-stimulatory molecules (CD40, CD80, CD86), CD83 and CCR7 as well as
reduced endocytic capacity. Phosphorylation of the p38 MAP kinase was not
induced in GA/d-cAMP-activated DCs. Accordingly, these cells secreted
significantly less IL-12p40 (p<0,001) then cytokine-activated cells. However,
the secretion of CCL3 was not inhibited, and IL-10 was not produced by those
cells. GA/d-cAMP-stimulated DCs efficiently activated antigen specific memory
Th1 cells in vitro. The number of Th1-polarised lymphocytes was lower, when
naive CD4+ T lymphocytes were stimulated with GA/d-cAMP-activated DCs compared
with cytokine-activated cells. 36 h after intradermal, but not after
subcutaneous re-injection, GA/d-cAMP-activated fluorescence-labeled DCs were
detected in the paracortical T-cell areas of the draining lymph nodes.
Similarly re-injected, GA/d-cAMP- and cytokine-activated protein antigen-
loaded DCs induced qualitatively similar Th-immune responses characterised by
the production of IL-2, IFN-gamma, TNF-alpha and IL-17. In addition, the
application of both GA/d-cAMP- and cytokine-activated DCs was followed by an
expansion of peripheral CD4+Foxp3+ regulatory T lymphocytes. The qualitatively
similar immune responses in vivo observed after the administration of
IL-12-deficient and IL-12-producing DCs could be explained by the fact that
the DCs might have received additional stimuli after the re-injection, e.g.,
through molecules of the extracellular matrix or CD40 ligand (CD40L), which
might have affected the properties of the DCs in vivo. In fact, GA/d-cAMP
activated DCs subsequently exposed to recombinant CD40L in vitro secreted IL-
12p40 and IL-23 to a similar extent as DCs previously stimulated with
cytokines. The induction of similar Th immune responses by IL-12-deficient and
IL-12-producing DCs in vivo as described in this work indicates that
IL-12-deficient DCs by means of other mechanisms, possibly through the
secretion of IL-23, are capable of inducing proinflammatory immune responses
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
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