1,721,040 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
Differential effect of acute and permanent heat shock protein 70 overexpression in tumor cells on lysability by cytotoxic T lymphocytes
No full textWe have shown previously that acute heat shock protein (Hsp) 70 induction in a human melanoma cell line containing a doxycycline-inducible Hsp70 expression construct increases lysability of these tumor cells by cytotoxic T lymphocyte (CTL) without interfering with MHC class I expression and antigen presentation. The same parental melanoma cell line has now been transduced retrovirally to overexpress Hsp70 permanently. Here we demonstrate that MHC class I cell surface expression is again not altered and that these cells, in contrast with acutely Hsp70 overexpressing cells, do not show augmentation of CTL-mediated apoptosis. Also, long-term induction of Hsp70 in cells with the doxycycline-inducible Hsp70 construct leads to abrogation of increased lysability. Because, furthermore, after heat shock the same permanently Hsp70 overexpressing cells show Hsp70 induction and increased lysability, it is hypothesized that acutely available Hsp70 is able to chaperone proteins that are involved in CTL-mediated apoptosis of target cells and to thereby improve their lysability. We also observed that permanent but not acute Hsp70 overexpression resulted in decreased levels of Hsc70, the constitutively expressed member of the Hsp70 family. Down-regulation of Hsc70 occurs at the post-transcriptional level and can be observed also after long-term induction of Hsp70 in cells containing the doxycycline-inducible expression system. Hsc70 down-regulation might reflect a functional integration of the overexpressed Hsp70 on the basis of a chaperone network so that only acute induction will provide Hsp70 that can improve tumor cell lysability. The implications of the differential effect of acute versus permanent Hsp70 overexpression for tumor therapy are discussed
Permanent Hsp70 overexpression in tumor cell lines does not affect MHC class I expression acid lysability by cytotoxic cells
No full textPermanent Hsp70 overexpression in tumor cell lines does not affect MHC class I expression acid lysability by cytotoxic cells
No full textUrinary tract injuries in patients with multiple trauma
No full textThis article mainly reviews urinary tract injuries in patients with multiple trauma. Approximately 10% of all traumatic injuries resulting from an external force will involve the genitourinary system. The article discusses mechanisms of injury, diagnosis, and therapeutical approaches for renal, ureteral, bladder, and urethral trauma. Due to the complexity of such injuries-despite several attempts to provide a standard strategy in trauma patients with urinary tract involvement-an individual and patient-specific-therapeutic approach is mandatory in most cases. However, the availability of classified guidelines may help the surgeon to reach the most accurate decision. Because of the similarity of American and European guidelines on urological trauma, this article adapts injury severity scales and classification from the American Association for the Surgery of Trauma
Differential effect of acute and permanent heat shock protein 70 overexpression in tumor cells on lysability by cytotoxic T lymphocytes
No full textWe have shown previously that acute heat shock protein (Hsp) 70 induction in a human melanoma cell line containing a doxycycline-inducible Hsp70 expression construct increases lysability of these tumor cells by cytotoxic T lymphocyte (CTL) without interfering with MHC class I expression and antigen presentation. The same parental melanoma cell line has now been transduced retrovirally to overexpress Hsp70 permanently. Here we demonstrate that MHC class I cell surface expression is again not altered and that these cells, in contrast with acutely Hsp70 overexpressing cells, do not show augmentation of CTL-mediated apoptosis. Also, long-term induction of Hsp70 in cells with the doxycycline-inducible Hsp70 construct leads to abrogation of increased lysability. Because, furthermore, after heat shock the same permanently Hsp70 overexpressing cells show Hsp70 induction and increased lysability, it is hypothesized that acutely available Hsp70 is able to chaperone proteins that are involved in CTL-mediated apoptosis of target cells and to thereby improve their lysability. We also observed that permanent but not acute Hsp70 overexpression resulted in decreased levels of Hsc70, the constitutively expressed member of the Hsp70 family. Down-regulation of Hsc70 occurs at the post-transcriptional level and can be observed also after long-term induction of Hsp70 in cells containing the doxycycline-inducible expression system. Hsc70 down-regulation might reflect a functional integration of the overexpressed Hsp70 on the basis of a chaperone network so that only acute induction will provide Hsp70 that can improve tumor cell lysability. The implications of the differential effect of acute versus permanent Hsp70 overexpression for tumor therapy 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
Modelling navigational knowledge by route graphs
Full text linkNavigation has always been an interdisciplinary topic of research, because mobile agents of different types are inevitably faced with similar navigational problems. Therefore, human navigation can readily be compared to navigation in other biological organisms or in artificial mobile agents like autonomous robots. One such navigational strategy, route-based navigation, in which an agent moves from one location to another by following a particular route, is the focus of this paper. Drawing on the research from cognitive psychology and linguistics, biology, and robotics, we present a simple, abstract formalism to express the key concepts of route-based navigation in a common scientific language. Starting with the distinction of places and route segments, we develop the notion of a route graph, which can serve as the basis for complex navigational knowledge. Implications and constraints of the model are discussed along the way, together with examples of different instantiations of parts of the model in different mobile agents. By providing this common conceptual framework, we hope to advance the interdisciplinary discussion of spatial navigation
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
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