1,721,070 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
Hypoxia and human genome stability: Downregulation of BRCA2 expression in breast cancer cell lines
Get PDFPreviously, it has been reported that hypoxia causes increased mutagenesis and alteration in DNA repair mechanisms. In 2005, an interesting study showed that hypoxia-induced decreases in BRCA1 expression and the consequent suppression of homologous recombination may lead to genetic instability. However, nothing is yet known about the involvement of BRCA2 in hypoxic conditions in breast cancer. Initially, a cell proliferation assay allowed us to hypothesize that hypoxia could negatively regulate the breast cancer cell growth in short term in vitro studies. Subsequently, we analyzed gene expression in breast cancer cell lines exposed to hypoxic condition by microarray analysis. Interestingly, genes involved in DNA damage repair pathways such as mismatch repair, nucleotide excision repair, nonhomologous end-joining and homologous recombination repair were downregulated. In particular, we focused on the BRCA2 downregulation which was confirmed at mRNA and protein level. In addition, breast cancer cells were treated with dimethyloxalylglycine (DMOG), a cell-permeable inhibitor of both proline and asparaginyl hydroxylases able to induce HIF-1α stabilization in normoxia, providing results comparable to those previously described. These findings may provide new insights into the mechanisms underlying genetic instability mediated by hypoxia and BRCA involvement in sporadic breast cancers. © 2013 Daniele Fanale et al
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
BIOMARKERS OF UROTHELIAL DAMAGE IN PATIENTS TREATED BY ADJUVANT INTRAVESICAL THERAPY
No full textIntroduction/Aim: Chemotherapy or BCG given intravesically
to prevent recurrence after transurethral resection (TUR) of
non-muscle invasive bladder cancer (NMI-BC) cause
frequent, sometime severe, local toxicity. As a consequence,
many patients do not complete the planned treatment (1). A
major challenge for the urologists is to identify an early biomarker of urothelial damage to recognize and prevent local
toxicity improving patient’s compliance. The purpose of our
research was to investigate the relation between urothelial
injury by intravesical treatment and the expression of
potential biomarkers in urine and/or in barbotage solution.
The urinary HB-EGF expression in interstitial cystitis has
been analyzed by a few studies (2, 3). As a preliminary step,
the variations of Fibronectin (FN), Epidermal Growth Factor-
Receptor (EGF-R) and Heparin-binding Epidermal Growth
Factor-like Growth Factor (HB-EGF) during intravesical
therapy and after the administration of a solution with the
potential role of urothelial repairing (hyaluronic acid and
chondroitin sulphate) were investigated. Patients and
Methods: the toxicity of intravesical therapy with mitomycin,
epirubicin or BCG was classified in 3 grades (absent,
moderate, severe). Urine and bladder washing solution during
intravesical therapy in 55 patients after NMI-BC TUR and in
10 healthy controls for a total of 200 samples were collected.
Total cellular RNA was isolated from the cell pellet using
miRNeasy Mini Kit (Qiagen®). FN and EGF-R gene
expression by Real Time quantitative PCR were analyzed.
The expression of HB-EGF was measured in urine samples
by ELISA (Abcam®). Results: In barbotage samples the FN
gene expression and the EGF-R levels in our patients were
respectively increased a median of 4.7 fold and decreased of
0.9 fold compared to controls. Before intravesical therapy and
in absence of local toxicity, gene expression increased 1.9
fold for FN and 1.1 fold for EGF-R. In contrast, in patients
with local toxicity due to intravesical therapy, the FN gene
expression levels increased to a median of 5.82 fold, while
EGF-R remained unchanged. The administration of
hyaluronic acid and chondroitin sulphate solution decreased
the mean FN gene expression from 3 to 0.6 fold, with
concomitant symptomatic relief. HB-EGF protein median
urine levels were 25.7 pg/ml in 13 patients before intravesical
therapy and 18.9 pg/ml in 5 healthy controls. No significant
variations in relation to the local toxicity. During therapy
median HB-EGF protein levels in urine varied from 21.6
pg/ml in absence of toxicity to 25.7 pg/ml in case of severe
toxicity to 18.5 pg/ml after hyaluronic acid and chondroitin
sulphate solution. Preliminarily, the observed variations of
HB-EGF, increasing no more than 1.2 fold compared to
healthy controls, do not seem possible marker of urothelial
damage. Discussion and Conclusion: EGF-R gene and HBEGF
expressions do not seem to vary significantly in relation
to local toxicity due to intravesical therapy. FN gene is
overexpressed in presence of urothelial damage significantly
reduced by intravesical hyaluronic acid and chondroitin
sulphate solution administration, according with symptoms
relief
Anti-endothelin drugs in solid tumors
No full textImportance of the field: The endothelin (ET) axis, which includes the biological functions of ETs and their receptors, has played a physiological role in normal tissue, acting as a modulator of vasomotor tone, tissue differentiation and development, cell proliferation and hormone production. Interestingly, it also functions in the growth and progression of various tumors. Several researchers have identified the blockade of the ET-1 receptor as a promising therapeutic approach. Areas covered in this review: The clinical investigation of an orally bioavailable ET antagonist, atrasentan, in prostate cancer, is encouraging. In this neoplasia, it has shown antitumor activity, bone metastasis control and amelioration of cancer-related pain but improvement in time to progression and overall survival has still not been demonstrated. The clinical trials of other ET antagonists are reported. Literature research was performed by Pubmed and Pharmaprojects. What the reader will gain: A comprehensive view about the use of atrasentan in the treatment of castration-resistant prostate cancer (CRPC) is provided together with the scientific rationale based on the function of ET and its receptor in various cancer development mechanisms. Take home message: Atrasentan seems to be active in CRPC, although strong scientific evidence is still to be found. Interesting clinical findings regard zibotentan. © 2010 Informa UK Ltd
R-Roscovitine (Seliciclib) prevents DNA damage-induced cyclin A1 upregulation and hinders non-homologous end-joining (NHEJ) DNA repair
No full text- …
