1,720,986 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
Coronavirus induced changes in mouse pathophysiology
No full textMasterarbeit - Veterinärmedizinische Universität Wien - 2022Diese Arbeit umfasst Ergebnisse von C57Bl/6 Mäuse welche nasal mit einem Mäusecoronavirus, welcher ein gutes Modell für eine Infektion mit SARS-CoV-2 darstellt, infiziert worden sind. Der Mäusecoronavirus ist ein Betacoronavirus und mit SARS-CoV-1 und 2 verwandt. Die Ergebnisse dieser Arbeit zeigen organspezifische Unterschiede in der Viruslast, da man die höchsten Werte am Tag 2 in der Lunge und an Tag 4 in der Leber sehen konnte. Die NET Bildung in der Lunge war am Tag 4 am höchsten, wobei in der Leber Thromben am Tag 2 und 10 gefunden werden konnten. Am Tag 4 war die Anzahl der Thromben in der Leber signifikant geringer. Diese Beobachtung führte zur Untersuchung von Interaktionspartnern in dem Gerinnungssystem, bei der hohe Werte von PAI-1 und uPA am Tag 4 beobachtet wurden. Weiters wurde der Entzündungsprozess in der Leber untersucht und eine Organkultur etabliert, welche die Resultate der in vivo Experimente ex vivo bestätigte. Die äußere Körpertemperatur wurde mit einer Infrarotkamera gemessen und mit dem Gewichtsverlust im Laufe einer Infektion verglichen. Das Mikrobiom, vor allem die ASF, von MCoV infizierten Mäusen wurde mit Kontrollmäusen verglichen, genauso wie das ASF von Mäusen aus der Quarantäne mit dem von Mäusen aus der SPF Haltung verglichen wurden. Die Ergebnisse zeigten, dass mithilfe einer qPCR und einem definierten sauberen Mikrobiom, Statusänderungen der ASF auf eine Infektion in Mäusen hinweisen können.Master thesis - University of Veterinary Medicine Vienna - 2022The main research topic of this master thesis is the analysis of host-pathogen interactions during a coronavirus infection. C57BL/6 mice were intranasally infected with the murine coronavirus (MCoV), which belongs to the same subgroup of betacoronaviruses as the human severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and is therefore a great model to translate findings in our mouse model to the human situation. Moreover, the model was sensitive enough that even a low dose virus infection resulted in a rapid influx of T-cells as well as macrophages in the lung, even though virus burden was not any more detectably. The hypothesis was, that the interaction between the murine coronavirus and its host results in changes in the body temperature, microbiome and a prolonged prothrombotic and inflammatory response. We observed differences in virus burden and presence of neutrophil extracellular trap (NET) derived thrombi between the lung and the liver. Lung virus burden was highest at day 2 with thrombi at day 10, whereas in the liver the virus burden was highest at day 4 with high thrombus numbers at day 2 and 10. qPCR analysis of inflammation markers of liver mRNA, like tumor necrosis factor alpha (TNFα), interferon gamma (IFNγ), or intracellular adhesion molecule 1 (ICAM-1) revealed that the highest inflammatory response could be seen at day 4. Moreover, collagen deposits in the lung were highest at day 4, whereas liver collagen was highest at day 10. As NET formation is paralleled by coagulation, also the coagulation factors and fibrinolytic players were investigated. Plasminogen activator inhibitor 1 (PAI-1) and urokinase plasminogen activator (uPA) mRNA were upregulated on day 4, which coincided with high plasma protein levels of TNFα and IFNγ. The induction of uPA and PAI-1 by these cytokines was confirmed in an ex vivo liver stimulation model. In line with the in vivo findings, PAI-1 and uPA mRNA were again increased in comparison to untreated organ culture, indicating that their expression was directly regulated by hepatic inflammation. Another aim was to identify if the outer body temperature, measured with an infrared camera, is a better indicator than body weight regarding the wellbeing. It could be shown that body weight was more suited as an early marker for wellbeing than the outer body temperature. However, a clear point of no return could be set with the infrared camera, which may support the decision if the animal should be euthanized or not. The last part of the thesis focused on alterations in the Altered Schaedler Flora (ASF) microbiota, which includes eight specific bacteria represented in the gut microbiome. Significant differences between control and MCoV infected mice as well as between mice from the Anna Spiegel Animal facility, which had SPF conditions, and the Quarantine, where mice were infected with Murine Norovirus, Pasteurella sp., Helicobacter sp. and protozoa were detected. In conclusion, we were able to demonstrate differences between the lung and the liver during an infection with MHV, observing the NET formation and inflammatory response. Furthermore our in vivo results were in line with ex vivo organ culture and we observed changes of the ASF during a virus infection
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
Platelet function under systemic oxidative stress
No full textNeben ihrer zentralen physiologischen Bedeutung für die primäre Hämostase und die plasmatische Blutgerinnung spielen Thrombozyten und ihr Aktivierungszustand eine entscheidende Rolle in der Entstehung und dem Fortschreiten atherosklerotischer Erkrankungen.
Eine Vielzahl an Befunden weist darauf hin, dass Lipoproteine - speziell LDL und HDL – imstande sind, die Thrombozytenaktivierung direkt zu beeinflussen. Hohe Plasmakonzentrationen von HDL gehen mit einer verminderten Thrombozytenreaktivität einher, während erhöhte Plasmakonzentrationen von LDL eng mit Thrombozytenhyperreaktivität korrelieren.
Da jedoch Lipoproteine von hypercholesterinämischen Patienten eine erhöhte Anfälligkeit für oxidative Modifizierung zeigen bleibt unklar, ob die in diesen Patienten zu beobachtende Thrombozytenaktivierung primär eine Folge der erhöhten LDL Konzentrationen oder eine Konsequenz der Lipoproteinoxidation ist.
In dieser Arbeit konnte gezeigt werden, dass nicht nur native HDL sondern auch native LDL einen inhibierenden Effekt auf Thrombozyten ausüben. Beide Lipoproteinklassen sind im Stande die durch verschiedene Agonisten verursachte Thrombozytenaggregation und Degranulierung abzuschwächen.
Nach Oxidation der Lipoproteine durch das in vivo vorkommende Oxidans Hypochlorit verlieren sowohl LDL als auch HDL ihren hemmenden Einfluss auf die Thrombozytenfunktion und entwickeln die Fähigkeit unabhängig von anderen Agonisten Thrombozytenaggregation, Degranulierung und GPIIb/IIIa Aktivierung hervorzurufen, wie auch die intrazelluläre VASP Phosphorylierung zu reduzieren. Darüber hinaus sind Hypochlorit-oxidierte LDL im Stande, die Expression von CD40L an der Thrombozytenoberfläche zu induzieren. Dieser Befund ist auch insofern von großem Interesse, als CD40L Entzündungen und prothrombotische Antworten hervorruft, welche für das Fortschreiten von atherosklerotischen Geschehnissen mitverantwortlich sind.
Die in dieser Arbeit präsentierten Daten weisen darauf hin, dass der Scavenger Rezeptors CD36 eine zentrale Rolle in der Interaktion von Thrombozyten mit oxidierten Lipoproteinen spielt, da das Blocken dieses Rezeptors zu einer starken Abschwächung der biologischen Wirkung oxidierter Lipoproteine auf die Thrombozyten führt.
Die hier vorgestellten Befunde unterstützen das Modell, dass oxidativer Stress in engem Zusammenhang mit (potentiell) pro-thrombotischen und pro-inflammatorischen Folgereaktionen steht und dass hierbei Thrombozyten wie auch Lipoproteine eine entscheidende Rolle einnehmen.Besides their important function in primary haemostasis and coagulation, platelets and their activation state play a pivotal role in the initiation and progression of atherosclerotic disease.
A wealth of evidence indicates that lipoproteins, especially low density lipoproteins (LDL) and high density lipoproteins (HDL), directly influence the activity state of platelets. It is generally accepted that high plasma levels of HDL inversely correlate with platelet hyperreactivity, whereat plasma levels of LDL show the opposite effect. Since hypercholesterolemic patients also show enhanced susceptibility to oxidative lipoprotein modification, it remains unclear if the underlying mechanism of platelet activation in these patients is a consequence of lipoprotein oxidation.
Results of this study indicate that not only native HDL but also native LDL have inhibitory effects on platelet activation. Both classes of lipoproteins are able to impair agonist-induced platelet aggregation and degranulation.
Upon oxidative modification of lipoproteins, which was performed by the in vivo occurring oxidant hypochlorite, not only LDL but also HDL invert their function and acquire the ability to independently trigger platelet aggregation, degranulation, GPIIb/IIIa activation and decrease of VASP phosphorylation. Moreover, hypochlorite-oxidised LDL upregulate expression of platelet CD40L. The latter is of special interest since (soluble) CD40L elicits inflammatory and pro-thrombotic responses that favour and accelerate the progression of atherosclerosis.
The results shown within this work clearly argue for a central role of scavenger receptor CD36 in the interaction of platelets with oxidised lipoproteins, since blocking of this receptor leads to a strong attenuation of all platelet-activating effects.
These novel findings further support the model that oxidative stress is closely related to potentially atherogenic events and that the interaction of platelets and lipoproteins might therefore play a pivotal role in the progression of these events
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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