1,720,983 research outputs found
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
Methotrexate-induced biochemical alterations of the folate and methyl-transfer pathway in the CNS
Get PDFMethotrexate (MTX), administered as high-dose infusion (3-5 g/m2) and/or intrathecally (3-12 mg) has been associated with neurotoxicity of unclear pathogenesis. It was investigated if the biochemical alterations of the folate and methyl-transfer pathway in the CSF of cancer patients following MTX treatment may play a role in neurotoxicity. Firstly, analytical methods using HPLC with UV and/or fluorescence detection for the measurement of reduced folates, MTX, S-adenosylmethionine (SAM) and S-adenosylhomocysteine (SAH) were developed and validated. Secondly, CSF samples from adult patients with primary central nervous system lymphoma (PCNSL) and two pediatric ALL populations were collected and analysed. From four PCNSL patients CSF samples were obtained on four or five subsequent days. A massive depletion of the CSF 5-methyl-THF concentration was observed at the end of the high-dose MTX infusion. A repletion occured following the administration of rescue. After intracerebroventricular MTX a gradual decrease of the reduced folate concentrations was observed from day to day. There was no significant alteration of the SAM and SAH concentration in the same time-period. One of the patients had clinical signs of neurotoxicity and lower 5-methyl-THF and SAM concentrations compared to others. In the pediatric ALL collectives sampling was performed one to three weeks after the last MTX therapy. It was observed that the concentrations of 5-methyl-THF and SAM were in the normal range two weeks after treatment with high-dose and intrathecal (i.th.) MTX followed by rescue. In contrast, in protocols with i.th. MTX only the 5-methyl-THF concentrations were significantly decreased 12 days after the first i.th. MTX administration whereas SAM was significantly decreased throughout the protocols. Three ALL patients manifested signs of neurotoxicity and had low levels of 5-methyl-THF and SAM during or shortly after toxicity. In conclusion, the results suggest that the biochemical alterations of the folate and methyl-transfer pathway may play an important role in the genesis of MTX-associated neurotoxicity
Charakterisierung spontaner Muriner Medulloblastome Im Heterozygoten Patched<sup>+/-</sup>-Knockout-Modell : Untersuchungen zu Histologie, Zellzyklus, Chemosensibilität und Promininexpression
Get PDFMedulloblastome sind die häufigsten malignen Hirntumore bei Kindern. Trotz einer Kombination aus operativer, Bestrahlungs- und Chemotherapie kann nur bei 50-70 % der Patienten ein ereignisfreies Überleben über 5 Jahre erzielt werden. Die aktuelle Therapie verursacht bei einem großen Teil der Patienten schwere Langzeitschäden. Angesichts dieser Situation ist es dringend erforderlich, die angewandten Methoden weiter zu verbessern und neue Therapieoptionen zu erforschen. Dabei wird eine große Hoffnung mit der Entwicklung von Medikamenten verbunden, die spezifisch auf essentielle molekulare Prozesse der Tumore einwirken. Die Identifikation und Charakterisierung von Tumorstammzellen haben eine enorme Bedeutung für das Verstehen der Tumorgenese und Entwicklung von neuen therapeutischen Strategien. In dieser Arbeit werden Methoden evaluiert, die es ermöglichen, die Wirkung von Substanzen auf Medulloblastome in vivo mit dem Pached+/--Knockout-Mausmodell zu analysieren. Eine genaue Verlaufsdokumentation konnte durch die intravitale Magnet Resonanz Tomographie ermöglicht werden. Wir führten an Maus-Medulloblastomen histologische Färbungen zur Darstellung von Proliferation, Apoptosen, Differenzierung und dem Stammzellmarker Prominin durch. Ergänzend wurden in vitro Versuche an einer murinen Medulloblastomlinie durchgeführt. Es konnten darüber hinaus Erkenntnisse über das Signalweg-spezifisch wirkende Cyclopamin gewonnen werden. Wir konnten allerdings bei Applikation von Cyclopamin allein keine Verringerung des Wachstums oder eine verstärkte Differenzierung bei manifester Tumorerkrankung feststellen. Unsere Zellkulturversuche erbrachten bei der Kombination von Cyclopamin und Etoposid bei einigen Konzentrationen eine Wirkungsverstärkung. Wir konnten Prominin-positive Zellen an histologischen Schnitten von Patched+/--Tumoren und innerhalb der Zelllinie SJMM4 darstellen. Die Zellzyklusanalyse zeigte, dass Prominin-positive Zellen der Linie SJMM4 häufiger als negative im Zellzyklus anzutreffen sind. Signalweg-spezifische Wirkstoffe stellen eine wichtige Perspektive für zukünftige Therapieoptionen dar
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
Ausmaß der funktionellen Beeinträchtigung bei Juveniler Idiopathischer Arthritis unter Etanercepttherapie
Get PDFMaterial und Methoden: Untersucht wurden Childhood Health Assessment Questionnaire (CHAQ), ANA, HLA-B27, Alter bei Krankheitsbeginn, aktuelles Alter, Alter bei Therapiebeginn, Geschlecht, Schmerzangabe, Anzahl aktiver Gelenke, PedACR-Score, Dauer der Morgensteifigkeit, BSG, CRP, globale Beurteilung des kindlichen Gesundheitszustands durch die Eltern, allgemeine Krankheitsaktivität durch den Arzt (10 cm VAS), Begleittherapie mit Methotrexat und Corticosteroiden und Anzahl benötigter Hilfsmittel.Ergebnisse: Bis 2006 wurden Daten von 474 Patienten gesammelt (systemische JIA 16,3%, seronegative Polyarthritis 29,0%, seropositive Polyarthritis 11,6%, persistent Oligoarthritis 3,2%, extended Oligoarthritis 15,6%, Enthesitis ass. Arthritis 10,6%, Psoriasisarthritis 6,6%, unklassifizierte JIA 7,2%). Bei 80,2% erfolgte eine Begleittherapie mit MTX. Der mittlere (±SD) CHAQ war 0,94 (±0,73), einer “moderate disability” entsprechend. Patienten mit systemischer Arthritis, Polyarthritis, extended Oligoarthritis, erhöhter BSG, erhöhtem CRP, größerer Anzahl aktiver Gelenke, prolongierter Morgensteifigkeit und höheren Scores im globalen Arzturteil hatten höhere CHAQ-Scores. In der univarianten Analyse zeigte sich eine signifikante Korrelation von Anzahl aktiver Gelenke, den Entzündungsparametern (BSG, CRP), der Schmerzangabe, der Selbst- und Fremdbeurteilung (VAS), der Dauer der Morgensteifigkeit und der Anzahl benötigter Hilfsmittel mit dem CHAQ (pZusammenfassung: Die funktionelle Beeinträchtigung verbessert sich unter Therapie mit Etanercept dramatisch bei Kindern mit JIA. Die Verbesserung tritt frühzeitig auf und zeigt bei Fortführung der Therapie eine weitere Zunahme über 24 Monate
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