1,720,977 research outputs found
Nonbacterial thrombotic endocarditis presenting as intracerebral hemorrhage.
Full text linkNonbacterial thrombotic endocarditis is a rare cause of valvular heart disease, most commonly associated with advanced malignancy. The morbidity of this kind of endocarditis lies in its tendency to embolize, while the valve function is usually preserved. The central nervous system is the most common site of embolization, leading to ischemic stroke. We report a case of nonbacterial thrombotic endocarditis complicated by intracerebral hemorrhage as the first manifestation of adenocarcinoma of the lung. The endocarditis led to severe aortic regurgitation. In view of the advanced stage of lung cancer, the patient refused further therapy. He passed away 3 weeks after first diagnosis of the adenocarcinoma
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
Determinants of axonal growth and their role in the injured adult nervous system
Full text linkVerletzungen des adulten zentralen Nervensystems ziehen schwerwiegende klinische Konsequenzen nach sich, da die Möglichkeiten zur funktionellen Kompensation minimal sind. Auch spontane Zellerneuerung, regeneratives axonales Wachstum und Wiederherstellung von synaptischen Kontakten werden kaum je festgestellt. Das Wissen über das sich entwickelnde und über das adulte Nervensystem wächst rasch, und während der letzten Jahrzehnte hat sich unser Verständnis von Neuropathologie gewandelt. Wir wissen nun, dass die fehlende funktionelle Erholung nach Verletzungen des Zentralnervensystems teilweise von Molekülen abhängt, welche die Nervenzellen umgeben. Dabei sind vor allem die Myelin- assoziierten, inhibierenden Moleküle zu erwähnen. Ausserdem fehlt verletzten Neuronen die Fähigkeit, ein Genexpressionsmuster zu aktivieren, das ihnen erlaubt, Axone zum Wachstum zu veranlassen. In dieser Dissertation werden bestimmende Faktoren des axonalen Wachstums untersucht und besprochen. Eine Möglichkeit, die mit dem Myelin zusammenhängende Wachstumshemmung teilweise zu überwinden, ist, die Bindung eines inhibitorischen Myelinbestandteils, Nogo-A, an seine neuronalen Rezeptoren zu blockieren, indem ein monoklonaler Antikörper, IN-1, verabreicht wird. Um die Effekte von IN-1 detailliert zu untersuchen, benutzen wir ein Tiermodell bei welchem wir Ratten den Kortikospinaltrakt einseitig durchtrennen. Wie früher gezeigt wurde, verstärken sich dabei strukturelle Plastizität und funktionelle Erholung. Wir zeigen zum ersten Mal auf der elektronenmikroskopischen Ebene, dass neu auswachsende Nervenfasern im verletzten adulten Zentralnervensystem fähig sind, histologisch intakte Synapsen zu bilden. Die intrazellulären Mechanismen, die es Neuronen erlauben, Axone auswachsen zu lassen, werden nach wie vor schlecht verstanden. Wir versuchen hier anhand von Gen-Chip-Analysen einen weiten Überblick über die Anpassung der Transkription nach axonalen Verletzungen zu gewinnen. Wir untersuchen die Genexpression von lumbalen dorsalen Ganglienzellen der adulten Ratte nach Verletzung der peripheren und auch der zentralen Nervenfasern. Die so gewonnenen Resultate vergleichen wir mit der Genexpression derselben Neuronenpopulation während der Embryonalentwicklung. Die periphere und die zentrale Axotomie lösen klar unterscheidbare Antworten im Zellkörper aus. Für beide Verletzungsmuster gilt, dass die Expression von mehr als 50 Genen reguliert wird. Im Vergleich mit der Embryonalenwicklung stellen wir fest, dass für die Regeneration von peripheren Nerven keine vollständige Rekapitulation des embryonalen Expressionsmusters nötig ist. Wir untersuchen auch die durch eine Verletzung ausgelösten Änderungen der Gen- und Protein-Expression genauer, dies anhand von zwei Genen, Glypican-1 und dem peripheren Benzodiazepin-Rezeptor (PBR). Unsere Resultate zeigen, dass sich die Antwort des Zellsomas auf Verletzungen nicht nur auf der Ebene der Transkription und Translation zeigt, sondern vielmehr auch in der Lokalisierung und im Transport der Proteine. Im Falle von Glypican-1 legen unsere Resultate nahe, dass dem Protein im Rahmen des axonalen Wachstums und der Richtungszuweisung von auswachsenden Neuriten, zum Beispiel durch die Beeinflussung von Slit-Robo-Interaktionen, eine Rolle zukommt. Wir liefern eine erste detaillierte Beschreibung der Expression der Mitglieder der Slit- und Robo-Familien in verletzten und unverletzten adulten dorsalen Ganglienzellen. Ebenso zeigen wir mit verschiedenen histologischen Techniken zum ersten Mal die Induktion von PBR nach einer Axotomie in dorsalen Ganglien, und zwar spezifisch in kleinkalibrigen Neuronen. Wir demonstrieren das Vorhandensein des intakten PBR mit Hilfe von Liganden-Bindungsversuchen. Zusammengefasst zeigen die in dieser Dissertation präsentierten Resultate, dass in Neuronen des adulten verletzten Nervensystems die Fähigkeit zur strukturellen Reorganisation und zum Aufbau von synaptischen Verbindungen erhalten bleibt, wenn ihre Umgebung es erlaubt. Wir beschreiben die Genexpression im Zellkörper, welche eine bestimmende Grösse der neuronalen Wachstumskapazität ist, nach neuronalen Verletzungen. Ausserdem zeigen wir, dass diese Antwort nicht auf die Transkription beschränkt bleibt, sondern auch post-transkriptionelle Mechanismen beinhaltet.
The clinical consequences of adult central nervous system injuries are extremely severe since there is only a minor capability for functional compensation and an almost complete absence of cell renewal and axonal re-growth and re-connection. The understanding of the developing and adult nervous system is progressing rapidly. In the past decades the growing comprehension has been continuously extended onto neuropathological conditions. We know now that the lack of recovery following injuries of the central nervous system is partly due to environmental, most importantly myelin- associated inhibitory factors, and partly to the inability of injured neurons to mount a gene expression profile that allows axonal growth. In this thesis determinants of axonal growth are examined and discussed. A way to partially overcome myelin-derived growth inhibition, is to prevent Nogo-A from binding to neuronal receptors by applying monoclonal antibody IN-1. To further investigate the effect of IN-1, rats with unilaterally injured cortical spinal tract were treated with IN-1. This approach was previously shown to enhance structural plasticity and functional recovery in the treated rats. Using light- and electron-microscopy, we show for the first time that outgrowing nerve fibers can form new, ultrastructurally intact synaptic contacts in the adult nervous system following an identical model as described above. The intracellular mechanisms that enable neurons to grow axons are poorly understood. Microarray analysis offers a way to screen for transcriptional adaptations following axonal injury. We investigate gene expression in lumbar dorsal root ganglia of the adult rat following central or peripheral nerve injury and compare the results with the developmental gene expression in the same population of neurons. Peripheral and central axotomy induce clearly distinguishable cell body responses. For both injury paradigms the expression for more than 50 genes is regulated. The comparison to developmental stages, when axonal outgrowth occurs, reveals that a complete recapitulation of a developmental gene expression pattern is not necessary for the regeneration of peripheral nerves. We further investigate injury-induced transcriptional and post-transcriptional changes, exemplified by two genes, glypican-1 and the peripheral benzodiazepine receptor (PBR). Our results show that the cell body response to injury is not restricted to changes in transcription and translation, but also involves post-translational effects, such as protein localization and transport. For glypican-1 the presented results support functions in axonal growth and guidance, e.g. by involvement in slit-robo interactions. We provide a first detailed description of the expression of slit and robo family members in the adult injured and non-injured dorsal root ganglion. Using different histological techniques we show for the first time the induction of the PBR specifically in small-diameter dorsal root ganglion neurons after nerve injury. Ligand binding studies indicate the presence of correctly assembled PBR following injury. In summary, the results reported in this study show evidence that neurons in the adult nervous system retain capacities for structural reorganization and re-connection following injury if faced with a permissive environment. We characterize the transcriptional cell body response of neurons to injury, an important determinant of the neuronal growth capacity. Additionally, we show that the cell body response is not simply regulated at the level of transcription but is specified by post-transcriptional mechanisms
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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